Fix Ubuntu package installation for nodejs >0.10.0

No longer attempt to install npm from the nodejs ppa
Nodejs now includes & conflicts with the npm package.
As the ppa now only contains 0.10.0, the npm package should no longer be installed.

tools/dependencies/launch_helper.sh

@@ -61,7 +61,7 @@ if [ $? -ne 0 ] || [ ! -x "$node" ]; then
             sudo apt-get install python-software-properties
             sudo add-apt-repository ppa:chris-lea/node.js
             sudo apt-get update
-            sudo apt-get install nodejs npm
+            sudo apt-get install nodejs
             ;;
             *)
             echo "--> node.js is missing, please install node.js from: http://nodejs.org"