krb5 commit [krb5-1.16]: Back off Travis build to default dist

https://github.com/krb5/krb5/commit/ad552c829ae5df4b2dc55f8dc0f5ace52a8226d1
commit ad552c829ae5df4b2dc55f8dc0f5ace52a8226d1
Author: Greg Hudson <[email protected]>
Date:   Thu Jan 18 16:56:12 2018 -0500

    Back off Travis build to default dist
    
    Travis appears to have deployed a testing xenial environment which
    runs a daemon that sometimes interferes with apt commands.  Remove the
    "dist: xenial" line so we run in the default, supported distribution
    (currently trusty).
    
    (cherry picked from commit 7011c2c5c027852138283f46416917cea41b96cb)

 .travis.yml |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index ec170ed..eb48036 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,8 +2,6 @@ language: c++
 
 sudo: required
 
-dist: xenial
-
 matrix:
   include:
   - compiler: clang