scripts: bump git_reviewer.pl --git-min-percent default

Bump up default percentage of commits required to be auto-picked for CC.
Seems from a bit of trial-and-error to come up with a more reasonable
list of CC's this way.

Signed-off-by: Rob Clark <robclark@freedesktop.org>
diff --git a/scripts/get_reviewer.pl b/scripts/get_reviewer.pl
index fed0f05..b08d186 100755
--- a/scripts/get_reviewer.pl
+++ b/scripts/get_reviewer.pl
@@ -37,7 +37,7 @@
 my $email_git_fallback = 1;
 my $email_git_min_signatures = 1;
 my $email_git_max_maintainers = 5;
-my $email_git_min_percent = 5;
+my $email_git_min_percent = 15;
 my $email_git_since = "1-year-ago";
 my $email_hg_since = "-365";
 my $interactive = 0;