gluon-core: fix pattern %v in opkg URLs (#1087)

package/gluon-core/luasrc/lib/gluon/upgrade/500-opkg

@@ -8,13 +8,13 @@ local util = require 'gluon.util'
 local subst = {}
 
 
-local f = io.popen('. /etc/openwrt_release; echo "$DISTRIB_CODENAME"; echo "$DISTRIB_TARGET"; echo "$DISTRIB_ARCH"')
+local f = io.popen('. /etc/openwrt_release; echo "$DISTRIB_CODENAME"; echo "$DISTRIB_RELEASE"; echo "$DISTRIB_TARGET"; echo "$DISTRIB_ARCH"')
 subst['%%n'] = f:read()
+subst['%%v'] = f:read():gsub('-SNAPSHOT', '')
 subst['%%S'] = f:read()
 subst['%%A'] = f:read()
 f:close()
 
-subst['%%v'] = util.trim(fs.readfile('/etc/openwrt_version'))
 subst['%%GS'] = site.site_code
 subst['%%GV'] = util.trim(fs.readfile('/lib/gluon/gluon-version'))
 subst['%%GR'] = util.trim(fs.readfile('/lib/gluon/release'))