package/belle-sip: remove package

belle-sip was only needed as a dependency of linphone, as is anyway
bundled in more recent versions of linphone, making a separate package
unnecessary.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

DEVELOPERS

@@ -1020,7 +1020,6 @@ F:	package/openzwave/
 
 N:	Fabrice Fontaine <fontaine.fabrice@gmail.com>
 F:	package/bearssl/
-F:	package/belle-sip/
 F:	package/belr/
 F:	package/boinc/
 F:	package/cairo/