dep(js-utils): detect old Edge browser and mark them as unsupported

package-lock.json

       "dev": true
     },
     "js-utils": {
-      "version": "github:jitsi/js-utils#0a8ea63983863e38d062f91fc42883270ccdb38c",
-      "from": "github:jitsi/js-utils#0a8ea63983863e38d062f91fc42883270ccdb38c",
+      "version": "github:jitsi/js-utils#8567f86ec2774ae1d1c47b22e3435928cf5d9771",
+      "from": "github:jitsi/js-utils#8567f86ec2774ae1d1c47b22e3435928cf5d9771",
       "requires": {
         "bowser": "2.7.0",
         "js-md5": "0.7.3",

package.json

     "async": "0.9.0",
     "current-executing-script": "0.1.3",
     "jitsi-meet-logger": "github:jitsi/jitsi-meet-logger#5ec92357570dc8f0b7ffc1528820721c84c6af8b",
-    "js-utils": "github:jitsi/js-utils#0a8ea63983863e38d062f91fc42883270ccdb38c",
+    "js-utils": "github:jitsi/js-utils#8567f86ec2774ae1d1c47b22e3435928cf5d9771",
     "lodash.isequal": "4.5.0",
     "sdp-transform": "2.3.0",
     "strophe.js": "1.2.16",