CrashHandler: Fix warnings about unused parameters

Change-Id: Ia5755eaf3af739a9f8f71b44c26170ca2cac740c
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/tools/qtcreatorcrashhandler/crashhandlersetup.cpp

@@ -146,6 +146,10 @@ CrashHandlerSetup::CrashHandlerSetup(const QString &appName,
                 strsignal(signalsToHandle[i]), Q_FUNC_INFO);
         }
     }
+#else
+    Q_UNUSED(appName);
+    Q_UNUSED(restartCap);
+    Q_UNUSED(executableDirPath);
 #endif // BUILD_CRASH_HANDLER
 }