Fixes: debugger: disable automatic loading list of source files

Details:  accounted for >60% startup time in some cases and was
presumably only needed as help for a fallback when setting breakpoints
with gdb 6.5 on Windows

src/plugins/debugger/gdbengine.cpp

@@ -1140,7 +1140,7 @@ void GdbEngine::handleAqcuiredInferior()
     #if defined(Q_OS_MAC)
     sendCommand("info pid", GdbInfoProc, QVariant(), NeedsStop);
     #endif
-    reloadSourceFiles();
+    //reloadSourceFiles();
     tryLoadCustomDumpers();
 
     #ifndef Q_OS_MAC
@@ -1297,7 +1297,7 @@ void GdbEngine::handleAsyncOutput(const GdbMi &data)
                  frame.findChild("func").data() + '%';
 
             QApplication::alert(q->mainWindow(), 3000);
-            reloadSourceFiles();
+            //reloadSourceFiles();
             sendCommand("-break-list", BreakList);
             QVariant var = QVariant::fromValue<GdbMi>(data);
             sendCommand("p 0", GdbAsyncOutput2, var);  // dummy