Increase Network3g "num" to 7 in suite_scheduler.ini.

BUG=chrome-os-partner:21893
TEST=`suite_scheduler.py --sanity`

Change-Id: Iff1cf3cce043e59f146a9bc7467ea092699d7519
Reviewed-on: https://gerrit.chromium.org/gerrit/65944
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Alex Miller <milleral@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
diff --git a/suite_scheduler.ini b/suite_scheduler.ini
index 32beda0..a65bd05 100644
--- a/suite_scheduler.ini
+++ b/suite_scheduler.ini
@@ -101,7 +101,7 @@
 suite: network3g
 branch_specs: >=R25
 pool: cellular
-num: 6
+num: 7
 
 [Network3g_tmobile]
 run_on: nightly