fix(zinit-install): simplify protocol pattern

[vladdoster]

Description

Simplify .zinit-setup-plugin-dir protocol pattern

How Has This Been Tested?

test_patterns=(' ' '' 'fgit' 'ftp' 'ftps' 'ftpx' 'ghttps' 'git' 'http' 'https' 'httpss' 'httpx' '  http' 'ssh' 'rsync')
protocol_pattern='(|ftp(|s)|git|http(|s)|rsync|ssh)'
for p in $test_patterns[@]; do
  url="${p}://test-url.com";
  if [[ ${url} = ${~protocol_pattern}://* ]]; then
    P -P "%F{green}pass%f: ${(qqq)p}"
  else
    P -P "%F{red}fail%f: ${(qqq)p}"
  fi
done

fail: " "
fail: "fgit"
pass: "ftp"
pass: "ftps"
fail: "ftpx"
fail: "ghttps"
pass: "git"
pass: "http"
pass: "https"
fail: "httpss"
fail: "httpx"
fail: "  http"
pass: "ssh"
pass: "rsync"

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• Bug fix (non-breaking change which fixes an issue)
• Documentation change
• New feature (non-breaking change which adds functionality)

Checklist:

• All new and existing tests passed.
• I have added tests to cover my changes.
• I have updated the documentation accordingly.