Typo in env hook bash

[Vineet Pandey]

The .so file is in devel/lib/ but in the bash file it points to :

 #! /bin/bash
export GAZEBO_PLUGIN_PATH="${GAZEBO_PLUGIN_PATH}:${CATKIN_ENV_HOOK_WORKSPACE}/devel" 

It should be :

 #! /bin/bash
export GAZEBO_PLUGIN_PATH="${GAZEBO_PLUGIN_PATH}:${CATKIN_ENV_HOOK_WORKSPACE}/lib/" 

Cheers!