deps: update lib-jitsi-meet to latest.

Update config.js to include the new codec preference options under videoQuality settings.

config.js

     // Note that it's not recommended to do this because simulcast is not
     // supported when  using H.264. For 1-to-1 calls this setting is enabled by
     // default and can be toggled in the p2p section.
+    // This option has been deprecated, use preferredCodec under videoQuality section instead.
     // preferH264: true,
 
     // If set to true, disable H.264 video codec by stripping it out of the
 
     // Specify the settings for video quality optimizations on the client.
     // videoQuality: {
+    //    // Provides a way to prevent a video codec from being negotiated on the JVB connection. The codec specified
+    //    // here will be removed from the list of codecs present in the SDP answer generated by the client. If the
+    //    // same codec is specified for both the disabled and preferred option, the disable settings will prevail.
+    //    // Note that 'VP8' cannot be disabled since it's a mandatory codec, the setting will be ignored in this case.
+    //    disabledCodec: 'H264',
+    //
+    //    // Provides a way to set a preferred video codec for the JVB connection. If 'H264' is specified here,
+    //    // simulcast will be automatically disabled since JVB doesn't support H264 simulcast yet. This will only
+    //    // rearrange the the preference order of the codecs in the SDP answer generated by the browser only if the
+    //    // preferred codec specified here is present. Please ensure that the JVB offers the specified codec for this
+    //    // to take effect.
+    //    preferredCodec: 'VP8',
     //
     //    // Provides a way to configure the maximum bitrates that will be enforced on the simulcast streams for
     //    // video tracks. The keys in the object represent the type of the stream (LD, SD or HD) and the values
         // iceTransportPolicy: 'all',
 
         // If set to true, it will prefer to use H.264 for P2P calls (if H.264
-        // is supported).
+        // is supported). This setting is deprecated, use preferredCodec instead.
         // preferH264: true
 
+        // Provides a way to set the video codec preference on the p2p connection. Acceptable
+        // codec values are 'VP8', 'VP9' and 'H264'.
+        // preferredCodec: 'H264',
+
         // If set to true, disable H.264 video codec by stripping it out of the
-        // SDP.
+        // SDP. This setting is deprecated, use disabledCodec instead.
         // disableH264: false,
 
+        // Provides a way to prevent a video codec from being negotiated on the p2p connection.
+        // disabledCodec: '',
+
         // How long we're going to wait, before going back to P2P after the 3rd
         // participant has left the conference (to filter out page reload).
         // backToP2PDelay: 5

package-lock.json

       }
     },
     "lib-jitsi-meet": {
-      "version": "github:jitsi/lib-jitsi-meet#15dcc57424cc937290e1963b8eb402c1fcf48ccb",
-      "from": "github:jitsi/lib-jitsi-meet#15dcc57424cc937290e1963b8eb402c1fcf48ccb",
+      "version": "github:jitsi/lib-jitsi-meet#7868a6c1855b76c18b22545e128366786faae321",
+      "from": "github:jitsi/lib-jitsi-meet#7868a6c1855b76c18b22545e128366786faae321",
       "requires": {
         "@jitsi/js-utils": "1.0.0",
         "@jitsi/sdp-interop": "1.0.3",

package.json

     "jquery-i18next": "1.2.1",
     "js-md5": "0.6.1",
     "jwt-decode": "2.2.0",
-    "lib-jitsi-meet": "github:jitsi/lib-jitsi-meet#15dcc57424cc937290e1963b8eb402c1fcf48ccb",
+    "lib-jitsi-meet": "github:jitsi/lib-jitsi-meet#7868a6c1855b76c18b22545e128366786faae321",
     "libflacjs": "github:mmig/libflac.js#93d37e7f811f01cf7d8b6a603e38bd3c3810907d",
     "lodash": "4.17.19",
     "moment": "2.19.4",