theme/gitline: set default $POWERLINE_PROMPT

Author: gaelicWizard

themes/gitline/gitline.theme.bash

@@ -1,6 +1,7 @@
-#!/usr/bin/env bash
-
-. "$BASH_IT/themes/gitline/powerline.base.bash"
+# shellcheck shell=bash
+# shellcheck disable=SC2034 # Expected behavior for themes.
+# shellcheck source-path=SCRIPTDIR/../gitline
+source "${BASH_IT?}/themes/gitline/powerline.base.bash"
 
 #For the logo(Uncomment if you want a logo before your name)
 #PROMPT_DISTRO_LOGO="💻"
@@ -67,5 +68,6 @@ IN_VIM_THEME_PROMPT_TEXT="vim"
 IN_TOOLBOX_THEME_PROMPT_COLOR=125
 IN_TOOLBOX_THEME_PROMPT_TEXT="⬢ "
 
+: "${POWERLINE_PROMPT:="user_info scm python_venv ruby node cwd"}"
 
 safe_append_prompt_command __powerline_prompt_command