Ios: Simplify code

Initialize pointer to nullptr and use that as indicator that IosConfiguration
was initialized instead of a static bool.

Change-Id: I7d1c5b38e25282d065ddeb4ba1415c28932aa64b
Reviewed-by: Vikas Pachdha <vikas.pachdha@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/ios/iosconfigurations.h

@@ -137,7 +137,7 @@ private:
     Utils::FileName m_developerPath;
     QVersionNumber m_xcodeVersion;
     bool m_ignoreAllDevices;
-    QFileSystemWatcher *m_provisioningDataWatcher;
+    QFileSystemWatcher *m_provisioningDataWatcher = nullptr;
     ProvisioningProfiles m_provisioningProfiles;
     DevelopmentTeams m_developerTeams;
 };