[xml2po] Don't return 0 when command line contains errors (Bug #413999)
[xml2po] Don't return 0 when command line contains errors (Bug #413999)

Distrotech/yelp-xsl,Distrotech/yelp-xsl,jnavila/gnome-doc-utils,jnavila/gnome-doc-utils,Distrotech/gnome-doc-utils,Distrotech/gnome-doc-utils