Revert "travis: Compile trusty with depends for now"

Thus building against system rather than depends libs

This reverts commit fa5ce3f10e.

.travis.yml

@@ -100,11 +100,12 @@ jobs:
         BITCOIN_CONFIG="--enable-zmq --with-gui=qt5 --enable-fuzz --enable-glibc-back-compat --enable-reduce-exports --enable-debug CXXFLAGS=\"-g0 -O2\""
 
     - stage: test
-      name: 'x86_64 Linux  [GOAL: install]  [trusty]  [depends for now]'
+      name: 'x86_64 Linux  [GOAL: install]  [trusty]  [no depends, only system libs]'
       env: >-
         HOST=x86_64-unknown-linux-gnu
         DOCKER_NAME_TAG=ubuntu:14.04
         PACKAGES="python3-zmq qtbase5-dev qttools5-dev-tools libicu-dev libpng-dev libssl-dev libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-test-dev libboost-thread-dev libdb5.1++-dev libminiupnpc-dev libzmq3-dev libprotobuf-dev protobuf-compiler libqrencode-dev"
+        NO_DEPENDS=1
         RUN_FUNCTIONAL_TESTS=false
         GOAL="install"
         BITCOIN_CONFIG="--enable-zmq --with-incompatible-bdb --with-gui=no"