Fix watch file: Don't report rc versions

debian/watch

@@ -1,4 +1,4 @@
 
 version=3
 opts=pgpsigurlmangle=s/$/.sig/ \
-    https://arthur.barton.de/pub/ngircd/ngircd-([0-9\.]+(?:~rc\d+)?)\.tar\.xz
+    https://arthur.barton.de/pub/ngircd/ngircd-([0-9\.]+)\.tar\.xz