Don't reset idle time when there is no camera movement (Fixes #3902)

apps/openmw/mwinput/inputmanagerimp.cpp

@@ -413,6 +413,8 @@ namespace MWInput
         {
             float xAxis = mInputBinder->getChannel(A_LookLeftRight)->getValue()*2.0f-1.0f;
             float yAxis = mInputBinder->getChannel(A_LookUpDown)->getValue()*2.0f-1.0f;
+            if (xAxis != 0 || yAxis != 0)
+            {
                 resetIdleTime();
 
                 float rot[3];
@@ -427,6 +429,7 @@ namespace MWInput
                     mPlayer->pitch(rot[0]);
                 }
             }
+        }
 
         // Disable movement in Gui mode
         if (!(MWBase::Environment::get().getWindowManager()->isGuiMode()