Fix variable login_banner_text setting in banner_etc_issue

The previously values with `'` would not work.

Author: Mab879

linux_os/guide/system/accounts/accounts-banners/banner_etc_issue/bash/shared.sh

@@ -1,6 +1,8 @@
 # platform = multi_platform_rhel,multi_platform_fedora,multi_platform_ol,multi_platform_rhv,multi_platform_sle,multi_platform_slmicro,multi_platform_ubuntu,multi_platform_almalinux
 
-login_banner_text='(bash-populate login_banner_text)'
+read -r -d '' login_banner_text <<'EOF' || true
+(bash-populate login_banner_text)
+EOF
 
 # Multiple regexes transform the banner regex into a usable banner
 # 0 - Remove anchors around the banner text