Drop optional parameters in RemoteCollection.cs

LibGit2Sharp/RemoteCollection.cs

@@ -140,14 +140,25 @@ public virtual void Remove(string name)
             Proxy.git_remote_delete(repository.Handle, name);
         }
 
+        /// <summary>
+        /// Renames an existing <see cref="Remote"/>.
+        /// </summary>
+        /// <param name="name">The current remote name.</param>
+        /// <param name="newName">The new name the existing remote should bear.</param>
+        /// <returns>A new <see cref="Remote"/>.</returns>
+        public virtual Remote Rename(string name, string newName)
+        {
+            return Rename(name, newName, null);
+        }
+
         /// <summary>
         /// Renames an existing <see cref="Remote"/>.
         /// </summary>
         /// <param name="name">The current remote name.</param>
         /// <param name="newName">The new name the existing remote should bear.</param>
         /// <param name="callback">The callback to be used when problems with renaming occur. (e.g. non-default fetch refspecs)</param>
         /// <returns>A new <see cref="Remote"/>.</returns>
-        public virtual Remote Rename(string name, string newName, RemoteRenameFailureHandler callback = null)
+        public virtual Remote Rename(string name, string newName, RemoteRenameFailureHandler callback)
         {
             Ensure.ArgumentNotNull(name, "name");
             Ensure.ArgumentNotNull(newName, "newName");