netdata/packaging/ci: Following hints from travis-ci/travis-ci#4681 a…

…nd the mayhem triggered from this change

So we adding the compiler, to see if it will get travis to build the right matrix.
then linter broke on addons for some weird reason, so remove addons->apt->update too

.travis.yml

@@ -2,6 +2,7 @@ os: linux
 dist: trusty
 sudo: true
 language: c
+compiler: gcc
 services:
 - docker
 
@@ -10,12 +11,6 @@ matrix:
   allow_failures:
     env: ALLOW_SOFT_FAILURE_HERE=true
 
-# Update the system before doing anything else
-#
-addons:
-  apt:
-    update: true
-
 # Install dependencies for all, once
 #
 install: