don't depend on doxygen as the docs are shipped with the tarball

debian/control

@@ -3,7 +3,7 @@ Section: shells
 Priority: extra
 Maintainer: ridiculous_fish <[email protected]>
 Uploaders: David Adam <[email protected]>, Siteshwar Vashisht <[email protected]>
-Build-Depends: debhelper (>= 8.0.0), libncurses5-dev, autoconf, doxygen, autotools-dev, dh-autoreconf, gettext
+Build-Depends: debhelper (>= 8.0.0), libncurses5-dev, autoconf, autotools-dev, dh-autoreconf, gettext
 Standards-Version: 3.9.1
 Homepage: http://fishshell.com/
 Vcs-Git: git://github.com/fish-shell/fish-shell.git