Fix client having too short a timeout in remote TLS usage

There was a 5 second timeout to establish basic connectivity, but
was mistakenly extended beyond that.  Re-establish default timeout
behavior after connectivity established.

confluent_client/confluent/client.py

@@ -154,6 +154,7 @@ class Command(object):
             try:
                 self.connection.settimeout(5)
                 self.connection.connect(sa)
+                self.connection.settimeout(None)
             except:
                 raise
                 self.connection.close()