Updated CHANGELOG

Author: Axel Dahlberg

CHANGELOG.md

@@ -6,6 +6,10 @@ For more details refer to the [documentation](https://softwarequtech.github.io/S
 Upcoming
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+2019-10-16 (v3.0.4)
+-------------------
+- If a CQCConnection does not manage to connect to the cqc server, the used app ID is popped from the list of used ones, to be reused again.
+
 2019-10-08 (v3.0.3)
 -------------------
 - Fixed bug that mixes up return messages for different application IDs