Handle Errno::ECONNREFUSED

Which happens if the socket file is hanging around but the server
process is gone.

Author: jonleighton

lib/spring/client/run.rb

@@ -26,7 +26,7 @@ def connect
       def call
         begin
           connect
-        rescue Errno::ENOENT, Errno::ECONNRESET
+        rescue Errno::ENOENT, Errno::ECONNRESET, Errno::ECONNREFUSED
           cold_run
         else
           warm_run