TT#123903 fix prev message pointer

* in the voicemail main loop vms->curmsg
  initial invalid pointer is set to -1 to cover
  scenarios where user presses '4' to listen a previous
  message, otherwise the pointer produces playback of an
  invalid message with the invalid counter

Change-Id: If3c69b1e1783b25e4e1fd10ecf96e0923a7178ce

debian/patches/series

@@ -27,3 +27,4 @@ sipwise_fix_app_voicemail_bugs.patch
 sipwise_vm_externnotify_by_uuid.patch
 sipwise_vm_hebrew_language_fixups.patch
 sipwise_vm_add_arabic_support.patch
+sipwise_vm_fix_prev_message.patch

debian/patches/sipwise_vm_fix_prev_message.patch

@@ -0,0 +1,10 @@
+--- a/apps/app_voicemail.c
++++ b/apps/app_voicemail.c
+@@ -12276,6 +12276,7 @@ static int vm_execmain(struct ast_channe
+ #endif
+ 
+ 	/* Add the vm_state to the active list and keep it active */
++	vms.curmsg = -1;
+ 	vms.lastmsg = -1;
+     vms.deleted = NULL;
+     vms.heard = NULL;