Fixing potential undefined variable error in client open

This change reorganizes some of the error handling code in the
client open routine, preventing the generation of an undefined
variable error. The net effect of the client open routine is
unchanged.

Fixes #199

kmip/services/kmip_client.py

@@ -210,6 +210,8 @@ class KMIPProxy(KMIP):
         self.logger.debug("KMIPProxy suppress_ragged_eofs: {0}".format(
             self.suppress_ragged_eofs))
 
+        last_error = None
+
         for host in self.host_list:
             self.host = host
             sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
@@ -221,11 +223,13 @@ class KMIPProxy(KMIP):
                 self.logger.error("An error occurred while connecting to "
                                   "appliance " + self.host)
                 self.socket.close()
+                last_error = e
             else:
                 return
 
         self.socket = None
-        raise e
+        if last_error:
+            raise last_error
 
     def _create_socket(self, sock):
         self.socket = ssl.wrap_socket(