Make the pre-commit Git hook executable.

This allows for symlinking it in .git/hooks/ directly[1] or executing
it from within an already existing `pre-commit` hook/script without
calling out to an interpreter in there[2], thus keeping up with any
upstream changes to it automatically.

Follow-up to e3b39b7233 / https://github.com/loot/loot/issues/622

[1] `ln -s ../../scripts/git/pre-commit .git/hooks/pre-commit`
[2] `./scripts/git/pre-commit` vs. `/bin/sh ./scripts/git/pre-commit`

resources/l10n/template.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: LOOT 0.9.2\n"
 "Report-Msgid-Bugs-To: https://github.com/loot/loot/issues\n"
-"POT-Creation-Date: 2016-08-04 18:29+0100\n"
+"POT-Creation-Date: 2016-08-04 21:46+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"