Drop depends on bash package

bash is an essential package, so no need to depend on it.

Fixes lintian report:

| E: ngcp-vmnotify: depends-on-essential-package-without-using-version depends: bash

From: Michael Prokop <mprokop@sipwise.com>

debian/control

@@ -8,6 +8,6 @@ Homepage: http://sipwise.com/
 
 Package: ngcp-vmnotify
 Architecture: all
-Depends: ${shlibs:Depends}, ${misc:Depends}, ngcp-sipsak, bash, uuid-runtime
+Depends: ${shlibs:Depends}, ${misc:Depends}, ngcp-sipsak, uuid-runtime
 Description: mwi generator for NGCP platform
  This program generates mwi notifications for the NGCP voicemail system.