Remove equals overrides from Remote

We previously removed the implementation for IEquatable, but
accidentally left the operator overloads. Get rid of them.

While in the area, remove an unused variable.

Author: carlosmn

LibGit2Sharp/Remote.cs

@@ -17,7 +17,6 @@ public class Remote : IBelongToARepository, IDisposable
         internal readonly Repository repository;
 
         private readonly RefSpecCollection refSpecs;
-        private string pushUrl;
 
         readonly RemoteHandle handle;
 
@@ -172,38 +171,6 @@ public virtual bool AutomaticallyPruneOnFetch
             }
         }
 
-        /// <summary>
-        /// Determines whether the specified <see cref="Object"/> is equal to the current <see cref="Remote"/>.
-        /// </summary>
-        /// <param name="obj">The <see cref="Object"/> to compare with the current <see cref="Remote"/>.</param>
-        /// <returns>True if the specified <see cref="Object"/> is equal to the current <see cref="Remote"/>; otherwise, false.</returns>
-        public override bool Equals(object obj)
-        {
-            return Equals(obj as Remote);
-        }
-
-        /// <summary>
-        /// Tests if two <see cref="Remote"/> are equal.
-        /// </summary>
-        /// <param name="left">First <see cref="Remote"/> to compare.</param>
-        /// <param name="right">Second <see cref="Remote"/> to compare.</param>
-        /// <returns>True if the two objects are equal; false otherwise.</returns>
-        public static bool operator ==(Remote left, Remote right)
-        {
-            return Equals(left, right);
-        }
-
-        /// <summary>
-        /// Tests if two <see cref="Remote"/> are different.
-        /// </summary>
-        /// <param name="left">First <see cref="Remote"/> to compare.</param>
-        /// <param name="right">Second <see cref="Remote"/> to compare.</param>
-        /// <returns>True if the two objects are different; false otherwise.</returns>
-        public static bool operator !=(Remote left, Remote right)
-        {
-            return !Equals(left, right);
-        }
-
         private string DebuggerDisplay
         {
             get