If you replace L11-L13 with something like the following, we correct the issue with the other mono package being installed. Removes the need for symlinking the mono executable in `/usr/local/bin` as well.

Extend ${COMMAND} like this:
```
MONO_PATH="/usr/local/mono/bin"
MONO="${MONO_PATH}/mono"
NZBDRONE="${INSTALL_DIR}/share/NzbDrone/NzbDrone.exe"
COMMAND="env PATH=${MONO_PATH}:${PATH} LD_LIBRARY_PATH=${INSTALL_DIR}/lib ${MONO} ${NZBDRONE}"
```