phusion/passenger release-6.0.6

Release 6.0.6

on GitHub

Update gemspec with up to date metadata.

Reverts the addition of the 'etc' gem to the Passenger gemspec, because it broke on normal ruby installs. Closes GH-2283.

Builds Ubuntu focal Nginx dynamic module package against Nginx 1.18.0. Closes GH-2291.

No longer providing prebuilt Ruby 2.1 or 2.2 binaries, they have been EOL for years and rubygems no longer supports them.

Updated various library versions used in precompiled binaries (used for e.g. gem installs):

• ccache 3.7.10 (was 3.7.9)
• Curl 7.71.1 (was 7.69.1)
• Git 2.27.0 (was 2.26.2)
• GnuPG 2.2.21 (was 2.2.20)
• libgpg_error 1.38 (was 1.37)
• libgcrypt 1.8.6 (was 1.8.5)
• RubyGems 3.1.4 (was 3.0.8)