Fix: Recreate disconnected connections when being retrieved (#19)

composer.json

@@ -22,7 +22,7 @@
     "php": "^7.4|^8.0",
     "illuminate/config": "~7.0|~8.0",
     "illuminate/support": "~7.0|~8.0",
-    "php-mqtt/client": "v1.0.0-rc1"
+    "php-mqtt/client": "^1.0"
   },
   "require-dev": {
     "squizlabs/php_codesniffer": "^3.5"

src/ConnectionManager.php

@@ -60,6 +60,12 @@ class ConnectionManager
             $name = $this->defaultConnection;
         }
 
+        // Remove the connection if it is in a disconnected state.
+        // Doing this instead of simply reconnecting ensures the caller will get a fresh connection.
+        if (array_key_exists($name, $this->connections) && !$this->connections[$name]->isConnected()) {
+            unset($this->connections[$name]);
+        }
+
         if (!array_key_exists($name, $this->connections)) {
             $this->connections[$name] = $this->createConnection($name);
         }