Qt: InputManager: don't enforce lower bound after a seek

Should fix problems like #2243.
After a seek, the updated position could be the keyframe position
choosen by demux, and then lower than A.

modules/gui/qt4/input_manager.cpp

@@ -951,11 +951,8 @@ void InputManager::setAtoB()
 /* Function called regularly when in an AtoB loop */
 void InputManager::AtoBLoop( float, int64_t i_time, int )
 {
-    if( timeB )
-    {
-        if( i_time >= timeB || i_time < timeA )
+    if( timeB && i_time >= timeB )
         var_SetTime( THEMIM->getInput(), "time" , timeA );
-    }
 }
 
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