[ticket/13792] Use hhvm instead of manually installing nightlys for now

Nightly builds are currently not supported because packages for precise
no longer exist and travis is still running on it.

PHPBB3-13792

travis/setup-webserver.sh

@@ -6,12 +6,6 @@
 set -e
 set -x
 
-if [ "$TRAVIS_PHP_VERSION" = 'hhvm' ]
-then
-	# Add PPA providing dependencies for recent HHVM on Ubuntu 12.04.
-	sudo add-apt-repository -y ppa:mapnik/boost
-fi
-
 sudo apt-get update
 sudo apt-get install -y nginx realpath
 
@@ -25,11 +19,9 @@ APP_SOCK=$(realpath "$DIR")/php-app.sock
 
 if [ "$TRAVIS_PHP_VERSION" = 'hhvm' ]
 then
-	# Upgrade to a recent stable version of HHVM
-	sudo apt-get -o Dpkg::Options::="--force-confnew" install -y hhvm-nightly
-
 	HHVM_LOG=$(realpath "$DIR")/hhvm.log
 
+    sudo service hhvm stop
 	sudo hhvm \
 		--mode daemon \
 		--user "$USER" \