convert: move svn config initializer out of the module level
The svn_config_get_config config call was being called at the module level, but
had the potential to throw permission denied errors if ~/.subversion/servers was
not readable. This could happen in certain test environments where the user
permissions were very particular.
This prevented the remotenames extension from loading, since it imports
convert's hg module, which imports convert's subversion module, which calls
this. The config is only ever used from this one constructor, so let's just move
it in to there.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..