network-security headline typo

Fix misspelled acronynm in headline.

A review in gedit spell check did not reveal other obvious typos.

Change-Id: I425d18f28697b758e6b01cedaa6f8e9c3b6ca6dd
Signed-off-by: Milton Miller <miltonm@us.ibm.com>
diff --git a/security/network-security-considerations.md b/security/network-security-considerations.md
index 1f5bb6d..f89621a 100644
--- a/security/network-security-considerations.md
+++ b/security/network-security-considerations.md
@@ -126,7 +126,7 @@
 
 [CA Law SB-327]: https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=201720180SB327
 
-## Services provided on TCP and UPD ports
+## Services provided on TCP and UDP ports
 
 ### TCP port 22 - Secure Shell (SSH) access to the BMC