Avoid crashing due to invalid sync messages

lib/src/main/java/de/kuschku/libquassel/session/ProtocolHandler.kt

@@ -30,6 +30,7 @@ import de.kuschku.libquassel.quassel.syncables.interfaces.ISyncableObject
 import de.kuschku.libquassel.quassel.syncables.interfaces.invokers.Invokers
 import de.kuschku.libquassel.util.compatibility.LoggingHandler.Companion.log
 import de.kuschku.libquassel.util.compatibility.LoggingHandler.LogLevel.DEBUG
+import de.kuschku.libquassel.util.compatibility.LoggingHandler.LogLevel.ERROR
 import java.io.Closeable
 
 abstract class ProtocolHandler(
@@ -117,6 +118,7 @@ abstract class ProtocolHandler(
   open fun onInitStatusChanged(progress: Int, total: Int) {}
 
   override fun handle(f: SignalProxyMessage.SyncMessage): Boolean {
+    try {
       val obj = objectStorage.get(f.className, f.objectName) ?: if (isInitializing) {
         syncQueue.add(f)
         return true
@@ -142,6 +144,9 @@ abstract class ProtocolHandler(
           currentCallSlot = ""
         }
       }
+    } catch (e: Exception) {
+      log(ERROR, "ProtocolHandler", "Exception occurred while processing $f", e)
+    }
     return true
   }