make sure to create LOGIN_CACHE_FILE

if file doesn't exist make sure to create it!
- RandomCoderOrg/ubuntu-on-android#182

Author: AnninoDr4

scripts/udroid/udroid.sh

@@ -56,6 +56,7 @@ _login() {
 	if [[ $avalible_distros =~ $distro ]]; then
 		if is_installed "$distro"; then
 			# store distro aliases in cache
+			[[ ! -f $LOGIN_CACHE_FILE ]] && touch $LOGIN_CACHE_FILE
 			echo "$distro" >"$LOGIN_CACHE_FILE"
 			# start distro
 			start "$distro" $extra_args