remove extra if clause

src/php/lib/Grpc/AbstractCall.php

@@ -129,17 +129,10 @@ abstract class AbstractCall
         if ($value === null) {
             return;
         }
-
-        // Proto3 implementation
-        if (is_array($this->deserialize)) {
-            list($className, $deserializeFunc) = $this->deserialize;
-            $obj = new $className();
-            $obj->mergeFromString($value);
-            return $obj;
-        }
-
-        // Protobuf-PHP implementation
-        return call_user_func($this->deserialize, $value);
+        list($className, $deserializeFunc) = $this->deserialize;
+        $obj = new $className();
+        $obj->mergeFromString($value);
+        return $obj;
     }
 
     /**