Remove ancient if-0'd code from libqof

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23205 57a11ea4-9604-0410-9ed3-97b8803252fd
Remove ancient if-0'd code from backends

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23206 57a11ea4-9604-0410-9ed3-97b8803252fd
Work around quote change in assertion messages

glib-2.38 changed the leading quote from ` to ', e.g.
"assertion `foo' failed" to "assertion 'foo' failed".

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23207 57a11ea4-9604-0410-9ed3-97b8803252fd