correctly cancel text fields when opening the menu (close #13169)

Sources/VLCDownloadViewController.m

@@ -105,6 +105,7 @@
 
 - (IBAction)goBack:(id)sender
 {
+    [self.view endEditing:YES];
     [[(VLCAppDelegate*)[UIApplication sharedApplication].delegate revealController] toggleSidebar:![(VLCAppDelegate*)[UIApplication sharedApplication].delegate revealController].sidebarShowing duration:kGHRevealSidebarDefaultAnimationDuration];
 }
 

Sources/VLCOpenNetworkStreamViewController.m

@@ -140,6 +140,7 @@
 
 - (IBAction)goBack:(id)sender
 {
+    [self.view endEditing:YES];
     [[(VLCAppDelegate*)[UIApplication sharedApplication].delegate revealController] toggleSidebar:![(VLCAppDelegate*)[UIApplication sharedApplication].delegate revealController].sidebarShowing duration:kGHRevealSidebarDefaultAnimationDuration];
 }