make connect retries configurable

fixes adafruit#14

Author: vladak

adafruit_minimqtt/adafruit_minimqtt.py

@@ -152,6 +152,7 @@ def __init__(
         ssl_context=None,
         use_binary_mode=False,
         socket_timeout=1,
+        connect_retries=5,
     ):
 
         self._socket_pool = socket_pool
@@ -166,6 +167,7 @@ def __init__(
             )
         self._socket_timeout = socket_timeout
         self._recv_timeout = recv_timeout
+        self._connect_retries = connect_retries
 
         self.keep_alive = keep_alive
         self._user_data = None
@@ -267,7 +269,7 @@ def _get_connect_socket(self, host, port, *, timeout=1):
         sock = None
         retry_count = 0
         last_exception = None
-        while retry_count < 5 and sock is None:
+        while retry_count < self._connect_retries and sock is None:
             retry_count += 1
 
             try: