tvheadend: drop the handwritten version override

The handwritten debian/changelog is only used to override the version
reported by support/version, but it is unnecessary and causes a version
mismatch:

- Build/Prepare feeds the raw git hash into debian/changelog, so the
  binary reports ddb984f4c17f4a26fd34f3e1b24e3323f9641b75~openwrt1
  instead of the package version 2026.08.17~ddb984f4.
- The CI package test then fails because it cannot find the package
  version in the output of any installed executable.
- Without .git, debian/changelog or rpm/version, support/version falls
  back to the source directory name.
- OpenWrt already names the source directory tvheadend-$(PKG_VERSION),
  so the binary correctly reports 2026.08.17~ddb984f4 without any
  override.

Alpine uses rpm/version in the same way and does not encode its own
package release into the version either.

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>

multimedia/tvheadend/Makefile

@@ -261,12 +261,6 @@ CONFIGURE_ARGS += \
 ##	--disable-libfdkaac_static \
 ##	--disable-pcloud_cache \
 
-define Build/Prepare
-	$(call Build/Prepare/Default)
-	echo 'Tvheadend $(shell echo $(PKG_SOURCE_VERSION) | sed "s/^v//")~openwrt$(PKG_RELEASE)' \
-		> $(PKG_BUILD_DIR)/debian/changelog
-endef
-
 define Package/tvheadend/conffiles
 /etc/config/tvheadend
 /etc/tvheadend