Qt: do not emit signals from the MIM constructor

Should close #14162

modules/gui/qt4/input_manager.cpp

@@ -1035,11 +1035,6 @@ MainInputManager::MainInputManager( intf_thread_t *_p_intf )
     /* Warn our embedded IM about input changes */
     DCONNECT( this, inputChanged( input_thread_t * ),
               im, inputChangedHandler() );
-
-    /* initialize p_input (an input can already be running) */
-    p_input = playlist_CurrentInput( THEPL );
-    if( p_input )
-        emit inputChanged( p_input );
 }
 
 MainInputManager::~MainInputManager()

modules/gui/qt4/qt4.cpp

@@ -499,7 +499,11 @@ static void *Thread( void *obj )
 
     /* Initialize the Dialog Provider and the Main Input Manager */
     DialogsProvider::getInstance( p_intf );
-    MainInputManager::getInstance( p_intf );
+    MainInputManager *mim = MainInputManager::getInstance( p_intf );
+    /* initialize p_input (an input can already be running) */
+    input_thread_t *p_input = playlist_CurrentInput( THEPL );
+    if( p_input )
+        mim->getIM()->inputChangedHandler();
 
 #ifdef UPDATE_CHECK
     /* Checking for VLC updates */