jingle: trim media attribute values

Movim has trailing whitespace around some of their media attributes

<source ssrc="1892824964" xmlns="urn:xmpp:jingle:apps:rtp:ssma:0">
  <parameter name="msid" value="{a98821d7-b298-4130-925a-ff6c510734c0} {f45dfc5c-2fa7-42b4-85e5-935e786b3feb} " xmlns="urn:xmpp:jingle:apps:rtp:ssma:0"/>
  <parameter name="cname" value="{63b1042b-5cb5-4411-b2a5-bdff92ae45be}" xmlns="urn:xmpp:jingle:apps:rtp:ssma:0"/>
</source>

our WebRTC doesn’t like that. We trim the value even though this seems to be a Movim bug.

src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnectionManager.java

@@ -438,7 +438,9 @@ public class JingleConnectionManager extends AbstractConnectionManager {
                     Log.d(
                             Config.LOGTAG,
                             account.getJid().asBareJid()
-                                    + ": no rtp session proposal found for "
+                                    + ": no rtp session ("
+                                    + sessionId
+                                    + ") proposal found for "
                                     + from
                                     + " to deliver proceed");
                     if (remoteMsgId == null) {

src/main/java/eu/siacs/conversations/xmpp/jingle/SessionDescription.java

@@ -291,7 +291,7 @@ public class SessionDescription {
                         throw new IllegalArgumentException(
                                 "A source specific media attribute is missing its value");
                     }
-                    mediaAttributes.put("ssrc", id + " " + parameterName + ":" + parameterValue);
+                    mediaAttributes.put("ssrc", id + " " + parameterName + ":" + parameterValue.trim());
                 }
             }