TT#66582 Remove explicit dependency on prosody, not necessary

The metapackage depends on ngcp-prosody-modules and this one already depends on
prosody, so while reviewing the changes necessary for the task we stumbled upon
these explicit dependencies on prosody and thought that it was better to remove
them (and the versions mentioned are out of date, in any case).

Change-Id: I72b70e4106c4def20fbffbb638bbe7f58eacce91

debian/control

@@ -372,7 +372,6 @@ Depends:
  ngcp-websocket-pro,
  nginx-light,
  ntp,
- prosody (>= 0.9.4~),
  python,
  redis-server,
  rsyslog,
@@ -459,7 +458,6 @@ Depends:
  ngcp-vmnotify,
  nginx-light,
  ntp,
- prosody (>= 0.9.4~),
  python,
  redis-server,
  rsyslog,
@@ -566,7 +564,6 @@ Depends:
  ngcp-websocket-pro,
  nginx-light,
  ntp,
- prosody (>= 0.9.4~),
  python,
  redis-server,
  rsyslog,