package/libass: bump version to 0.13.0

Quote from https://github.com/libass/libass/blob/master/Changelog
"* Drop ENCA support"

Therefore we remove the dependency to libenca.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libass/libass.hash

@@ -1,2 +1,2 @@
 # Locally computed
-sha256 a67c54ebaf5ec19ae72e86259ee6ab6adfe2e64ed9f9149db03dc863360ea38c  libass-0.12.3.tar.xz
+sha256	e0071a3b2e95411c8d474014678368e3f0b852f7d663e0564b344e7335eb0671	libass-0.13.0.tar.xz

package/libass/libass.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBASS_VERSION = 0.12.3
+LIBASS_VERSION = 0.13.0
 LIBASS_SOURCE = libass-$(LIBASS_VERSION).tar.xz
 # Do not use the github helper here, the generated tarball is *NOT*
 # the same as the one uploaded by upstream for the release.
@@ -38,11 +38,4 @@ else
 LIBASS_CONF_OPTS += --disable-harfbuzz
 endif
 
-ifeq ($(BR2_PACKAGE_LIBENCA),y)
-LIBASS_DEPENDENCIES += libenca
-LIBASS_CONF_OPTS += --enable-enca
-else
-LIBASS_CONF_OPTS += --disable-enca
-endif
-
 $(eval $(autotools-package))