Drop requirement for OTC review

Current bylaws under general policies:
https://github.com/openssl/general-policies/blob/master/policies/committer-policy.md

Indicate the following:
```
All submissions must be reviewed and approved by at least two committers.
Neither of the reviewers can be the author of the submission.
```

Given that, it seems we should adjust our tooling to reflect the lack of
need for an OTC approval

Reviewed-by: Matt Caswell <[email protected]>
Reviewed-by: Tomas Mraz <[email protected]>
(Merged from #217)

Author: nhorman

review-tools/gitaddrev

@@ -35,7 +35,7 @@ my $authorcount = 0;
 # be counted as reviewers.  For all other values, it works as a minimum.
 my $min_authors = 0;            # Main source default
 my $otccount = 0;
-my $min_otc = 1;                # Main source default
+my $min_otc = 0;                # Main source default
 my $omccount = 0;
 my $min_omc = 0;                # Main source default
 my $author = $ENV{GIT_AUTHOR_EMAIL};