Explicitly set c2s_require_encryption to false

Jitsi Meet doesn't seem to work with c2s_require_encryption set to true.
c2s_require_encryption is false by default. However it is possible that
in some Prosody configurations it is overriden by a global config to be
true. In that case Jitsi Meet might not work out-of-box. So let's set it
explicitly to be sure it is correct.

doc/debian/jitsi-meet-prosody/prosody.cfg.lua-jvb.example

             "ping"; -- Enable mod_ping
         }
 
+        c2s_require_encryption = false
+
 Component "conference.jitmeet.example.com" "muc"
     --modules_enabled = { "token_verification" }
 admins = { "focusUser@auth.jitmeet.example.com" }

doc/example-config-files/prosody.cfg.lua.example

 		certificate = "/var/lib/prosody/jitsi.example.com.crt";
 	}
 
+	c2s_require_encryption = false
+
 ------ Components ------
 -- You can specify components to add hosts that provide special services,
 -- like multi-user conferences, and transports.

doc/manual-install.md

         "bosh";
         "pubsub";
     }
+    c2s_require_encryption = false
 ```
 - add domain with authentication for conference focus user:
 ```