Update SMF image to fix crash

Crash was seen if DBStore was not enabled.
Also updated SMF readme.

Change-Id: I1be67a3a90208362b20c38cde38f3f36884fe821
diff --git a/5g-control-plane/Chart.yaml b/5g-control-plane/Chart.yaml
index d30d878..df49e3b 100644
--- a/5g-control-plane/Chart.yaml
+++ b/5g-control-plane/Chart.yaml
@@ -10,7 +10,7 @@
 name: 5g-control-plane
 icon: https://guide.opencord.org/logos/cord.svg
 
-version: 0.7.14
+version: 0.7.15
 
 dependencies:
   - name: mongodb