Nimble: Check stack initialization status before executing stack command

    Previous commit added checks in some functions that can be called
    without stack initalization. Corrected such instances.

components/bt/host/nimble/nimble

@@ -1 +1 @@
-Subproject commit 554cd264cd028886411b183885bb21b47b8901a6
+Subproject commit 1dc1ec6e76b0ab3bf93cc9f1ff7a2a09141e7c61