Fixed locale issue, do not parse for string.

Signed-off-by: Dan Schaper <dan.schaper@pi-hole.net>

automated install/basic-install.sh

@@ -2041,7 +2041,7 @@ get_available_branches() {
 
     cd "${directory}" || return 1
     # Get reachable remote branches, but store STDERR as STDOUT variable
-    output=$( { git remote show origin | grep 'tracked' | sed 's/tracked//;s/ //g'; } 2>&1 )
+    output=$( { git ls-remote --head --quiet | cut -d'/' -f3- -; } 2>&1 )
     echo "$output"
     return
 }