fixes #11719 - mysql2 dep must match ActiveRecord's runtime dep

When AR loads the mysql2 adapter, it calls 'gem' with a version spec.
For our bundle to include a compatible version of mysql2 and not the
latest version, the spec needs to match AR's.

(cherry picked from commit 47604a20219bdf0f6c72fde9dabd3f47f0513364)

Release 1.7.5

Fixes #10025 - move generic taxonomies code to base class

(cherry picked from commit bf75590c49c05dd780df388908598c85fc8f53bd)

Conflicts:
app/models/host/base.rb
app/models/host/managed.rb

Fixes #9947 - restrict user taxonomies if none is set

(cherry picked from commit abe910f2a46f4ecc1f349263d0b4751ed46ff200)

Conflicts:
app/models/report.rb
test/unit/host_test.rb

fixes #9941 - pin wirb to 1.x

Cherry picked part of 51a8843830a66f00c2194e27b79b059c92759dcb

Release 1.7.4

fixes #9851 - pin gettext_i18n_rails_js to 0.x

Cherry picked part of 51a8843830a66f00c2194e27b79b059c92759dcb

refs #9795 - revert string change

fixes #9469 - redirect to reports#index on destroy

(cherry picked from commit 0b1dafbbef20e185a9e4fdda626796db4a6168bd)

Conflicts:
test/integration/report_test.rb

fixes #9795 - check if mail is enabled before sending a notification

(cherry picked from commit 7ca39b3442be76da89c2c52d8da0c2d6afb74af1)