Fix a minor error in watch file.

Seems to work anyway

debian/watch

 version=4
-opts=filenamemangle=s/.+\/v?(\d\S+)\.tar\.gz/<project>-$1\.tar\.gz/,\
+opts=filenamemangle=s/.+\/v?(\d\S+)\.tar\.gz/netbeans-$1\.tar\.gz/,\
  uversionmangle=s/(\d)[_\.\-\+]?((RC|rc|pre|dev|beta|alpha|vc)\d*)$/$1~$2/ \
   https://github.com/apache/netbeans/tags .*/v?(\d\S+)\.tar\.gz