network stream VC: allow keeping up to 100 recently played URLs instead of 15

(cherry picked from commit 63081a97)

Sources/VLCOpenNetworkStreamViewController.m

@@ -143,7 +143,7 @@
             if ([_recentURLs indexOfObject:self.urlField.text] != NSNotFound)
                 [_recentURLs removeObject:self.urlField.text];
 
-            if (_recentURLs.count >= 15)
+            if (_recentURLs.count >= 100)
                 [_recentURLs removeLastObject];
             [_recentURLs addObject:self.urlField.text];