Remove "under construction" mark from release notes

V1.14 is completed and in a final test state.

RELEASE_NOTES.md

@@ -1,6 +1,6 @@
-Release Notes v1.14 (under construction)
+Release Notes v1.14
 ===
-### Objectives: *mbedTLS, log filtering*
+### Objectives: *mbedTLS, Lua API enhancements, log filtering*
 
 Changes
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