Specific rescue.

Thanks @beedub.

Author: djanowski

lib/redis/client.rb

@@ -476,7 +476,7 @@ def check(client)
           # recently and this client should work with old stuff.
           begin
             role = client.call([:role])[0]
-          rescue
+          rescue Redis::CommandError
             # Assume the test is passed if we can't get a reply from ROLE...
             role = @role
           end