IOSAD-12 Trigger empty attachments check in tests

pEpObjCTests/PEPInternalSessionTest.m

@@ -652,6 +652,7 @@
     msg.shortMessage = @"Mail to Myself";
     msg.longMessage = @"This is a text content";
     msg.direction = PEPMsgDirectionOutgoing;
+    msg.attachments = @[];
 
     NSNumber *numRating = [self testOutgoingRatingForMessage:msg session:session error:&error];
     XCTAssertNotNil(numRating);

pEpObjCTests/TestUtils/PEPTestUtils.m

@@ -85,6 +85,7 @@ const NSInteger PEPTestInternalSyncTimeout = 20;
     message.direction = outgoing ? PEPMsgDirectionOutgoing : PEPMsgDirectionIncoming;
     message.shortMessage = shortMessage;
     message.longMessage = longMessage;
+    message.attachments = @[];
     return message;
 }