Make correct test and proper use of append #33

Common/NMEASentenceCollector.cpp

@@ -108,10 +108,10 @@ bool CNMEASentenceCollector::getDataInt(std::string& data)
     std::string fromCall = getMyCall1();
     CAPRSUtils::dstarCallsignToAPRS(fromCall);
 
-  	// 20230425 Fix for https://github.com/F4FXL/DStarGateway/issues/33
+    // 20230425 Fix for https://github.com/F4FXL/DStarGateway/issues/33
     size_t hyphenIndex = fromCall.find('-');
-    if(hyphenIndex != std::string::npos) {
+    if(hyphenIndex == std::string::npos) {
-        fromCall = fromCall.append("-5");
+        fromCall.append("-5");
 	}
 
     std::string aprsFrame(fromCall);