adjusted message

Author: h5aaimtron

src/Http/Http/src/BindingAddress.cs

@@ -220,7 +220,7 @@ public static BindingAddress Parse(string address)
                 }
                 else
                 {
-                    throw new FormatException($"Invalid port: '{portString}', only numbers are allowed'");
+                    throw new FormatException($"Invalid port: '{portString}', only numbers are allowed.");
                 }
             }