Add libgconf-2-4 to debian/install_dependencies.sh (#6495)

This commit adds libgconf-2-4 to the `apt install` command in the
`install_dependencies.sh` script for Debian in
`scripts/linux/debian`.

Tested on Debian 10.2 (buster).

Closes #6493.

scripts/linux/debian/install_dependencies.sh

@@ -37,7 +37,7 @@ fi
 
 
 echo "installing OF dependencies"
-apt-get install freeglut3-dev libasound2-dev libxmu-dev libxxf86vm-dev g++ libgl1-mesa-dev libglu1-mesa-dev libraw1394-dev libudev-dev libdrm-dev libglew-dev libopenal-dev libsndfile-dev libfreeimage-dev libcairo2-dev libfreetype6-dev libssl-dev libpulse-dev libusb-1.0-0-dev libgtk${GTK_VERSION}-dev libopencv-dev libegl1-mesa-dev libgles1 libgles2-mesa-dev libassimp-dev librtaudio-dev libboost-filesystem-dev libglfw3-dev  liburiparser-dev libcurl4-openssl-dev libpugixml-dev libpoco-dev
+apt-get install freeglut3-dev libasound2-dev libxmu-dev libxxf86vm-dev g++ libgl1-mesa-dev libglu1-mesa-dev libraw1394-dev libudev-dev libdrm-dev libglew-dev libopenal-dev libsndfile-dev libfreeimage-dev libcairo2-dev libfreetype6-dev libssl-dev libpulse-dev libusb-1.0-0-dev libgtk${GTK_VERSION}-dev libopencv-dev libegl1-mesa-dev libgles1 libgles2-mesa-dev libassimp-dev librtaudio-dev libboost-filesystem-dev libglfw3-dev  liburiparser-dev libcurl4-openssl-dev libpugixml-dev libpoco-dev libgconf-2-4
 exit_code=$?
 if [ $exit_code != 0 ]; then
     echo "error installing dependencies, there could be an error with your internet connection"