fix port issue

Author: brentru

adafruit_minimqtt/adafruit_minimqtt.py

@@ -203,6 +203,7 @@ def __init__(
         self.on_subscribe = None
         self.on_unsubscribe = None
 
+    # pylint: disable=too-many-branches
     def _get_connect_socket(self, host, port, *, timeout=1):
         """Obtains a new socket and connects to a broker.
         :param str host: Desired broker hostname
@@ -222,6 +223,9 @@ def _get_connect_socket(self, host, port, *, timeout=1):
         if self._ssl_context is None:
             self._ssl_context = _fake_context
 
+        if not isinstance(port, int):
+            raise RuntimeError("Port must be an integer")
+
         if port == 8883 and not self._ssl_context:
             raise RuntimeError(
                 "ssl_context must be set before using adafruit_mqtt for secure MQTT."