Revert ESP-MQTT (#508)

* Revert ESP-MQTT

* Revert ESP-MQTT

* Update sdkconfig.defaults

lib/espMqttClient/.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,34 @@
+---
+name: Bug report
+about: Create a report to help us improve espMqttClient
+title: "[BUG]"
+labels: ''
+assignees: ''
+
+---
+
+#### Do not use to discuss topics! 
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+Which platform, esp8266 or esp32?
+Do you use TLS or not?
+Do you use an IDE (Arduino, Platformio...)?
+Which version of the Arduino framework?
+
+Please include any debug output and/or decoded stack trace if applicable.
+
+**Expected behaviour**
+A clear and concise description of what you expected to happen.
+
+**To Reproduce**
+Steps to reproduce the behaviour:
+
+**Example code**
+```cpp
+// Put code here to reproduce the bug, if possible
+```
+
+**Additional context**
+Add any other context about the problem here.