Make addition of config object specific to gltf files

Signed-off-by: Justin Georgi <justin.georgi@gmail.com>

includes/GlModelHooks.php

@@ -130,20 +130,23 @@ class GlModelHooks {
      * @param SpecialUpload $uploadFormObj current SpecialUpload object
      */
     public static function onUploadFormBeforeProcessing( $uploadFormObj ) {
-        $uploadFormObj->mComment .= <<<CONF
+        preg_match('/(glb|gltf)$/', $uploadFormObj->mUpload->getTitle(), $isGltf);
-        
+        if ($isGltf) {
-        <mvconfig>
+            $uploadFormObj->mComment .= <<<CONF
-        {
+            
-        "viewerConfig": {
+            <mvconfig>
-            "default": {
+            {
-            "camera-controls": true
+            "viewerConfig": {
+                "default": {
+                    "camera-controls": true
+                }
+            },
+            "annotations": {},
+            "annotationSets": {}
             }
-        },
+            </mvconfig>
-        "annotations": {},
+            CONF;
-        "annotationSets": {}
         }
-        </mvconfig>
-        CONF;
 
         return true;
     }