bash/init: Add git prompt support on Debian

The path of the file that defines __git_ps1 is different on Debian, so
we must check its presence and source it, if the first one (for Fedora)
is not present.
Signed-off-by: Cédric Marie <cedric@hjuvi.fr.eu.org>

bash/init

@@ -23,9 +23,13 @@ fi
 
 # Define aliases
 source $PAINTED_SHELL_PATH/bash/alias
-# Load git prompt support (__git_ps1) on Fedora
+# Load git prompt support (__git_ps1)
 if [ -f /usr/share/git-core/contrib/completion/git-prompt.sh ]; then
+    # Fedora
     source /usr/share/git-core/contrib/completion/git-prompt.sh
+elif [ -f /usr/lib/git-core/git-sh-prompt ]; then
+    # Debian
+    source /usr/lib/git-core/git-sh-prompt
 fi
 # Set colorful prompt
 if [ "$TERM" != "" ]; then