overly complicated commands in installer script.deb.sh

Summary

Some commands in the installer script look overly complicated.

Steps to reproduce

Search for "lsb_release" and "awk" in https://packages.gitlab.com/gitlab/gitlab-ce/install

Expected behavior

• To omit the field title for lsb_release: -s or --short
• To convert american letters to lowercase: tr A-Z a-z

Actual behavior

• Field title from lsb_release is output and piped to cut -f2 in order to be removed in an extra step..
• To convert american letters to lowercase, a full-blown awk is invoked.

Relevant logs and/or screenshots

Output of checks

Results of GitLab application Check

Results of GitLab environment info

Possible fixes

see expectations.