Revert "Use Default dispatcher instead of Main in Community scope."

This reverts commit 6a40fa2.

Author: InvictusRMC

ipv8/src/main/java/nl/tudelft/ipv8/Community.kt

@@ -73,7 +73,7 @@ abstract class Community : Overlay {
         network.blacklist.addAll(DEFAULT_ADDRESSES)
 
         job = SupervisorJob()
-        scope = CoroutineScope(Dispatchers.Default + job)
+        scope = CoroutineScope(Dispatchers.Main + job)
 
         if (evaProtocolEnabled)
             evaProtocol = EVAProtocol(this, scope)