Do not ignore existing mplayer installation

Stupid mistake with unless
Merge branch 'master' of git://github.com/mxcl/homebrew
scm-manager 1.31

Closes #20195.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
ghc: fix testsuite download

Fixes #20194.
plenv 1.9.4

Closes #20190.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
MPlayerShell 0.9.1

Closes #20193.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
libmxml: update download URL

Fixes #20191.
Merge branch 'master' of github.com:vhbit/homebrew
Merge branch 'master' of github.com:vhbit/homebrew into mplayershell