Remove community call reference

Community call was canceled here:
https://lists.ozlabs.org/pipermail/openbmc/2019-July/017225.html

Change-Id: Ida0815bc4ebc8db9151aa0b44ad4f74edb69c8a4
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index c40c2b6..c370a2d 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -121,7 +121,7 @@
 
 If you are planning a new function, you should get agreement that your
 change will be accepted.  As early as you can, introduce the change
-via the OpenBMC community call, IRC channel, or email list to start
+via the OpenBMC IRC channel or email list to start
 the discussion.  You may find a better way to do what you need.
 
 Stage your change in small pieces to make them easy to review: