Fix deprecation with isMethodSafe

Author: jderusse

src/Http/RequestMatcher/UnsafeRequestMatcher.php

@@ -18,6 +18,14 @@ class UnsafeRequestMatcher implements RequestMatcherInterface
 {
     public function matches(Request $request)
     {
-        return !$request->isMethodSafe(false);
+        // hack needed for compatibility with SF 3.4 => 4.3
+        // sf 3.4 => isMethodSafe(false)
+        // sf 4.3 => isMethodSafe() or isMethodSafe(false)
+        // sf 4.4 => isMethodSafe()
+        if (method_exists($request, 'getPreferredFormat')) {
+            return !$request->isMethodSafe();
+        } else {
+            return !$request->isMethodSafe(false);
+        }
     }
 }