Download JSON file from Prusa3d repository

As the PR https://github.com/prusa3d/Arduino_Boards/pull/1 is merged it makes sense to switch also in PF-build.sh to prusa3d Arduino_Boards repository.

PF-build.sh

@@ -212,9 +212,9 @@ ARDUINO_ENV="1.8.5"
 BUILD_ENV="1.0.6"
 BOARD="PrusaResearchRambo"
 BOARD_VERSION="1.0.1"
-BOARD_URL="https://raw.githubusercontent.com/DRracer/Arduino_Boards/master/IDE_Board_Manager/package_prusa3d_index.json"
+BOARD_URL="https://raw.githubusercontent.com/prusa3d/Arduino_Boards/master/IDE_Board_Manager/package_prusa3d_index.json"
 BOARD_FILENAME="prusa3drambo"
-BOARD_FILE_URL="https://raw.githubusercontent.com/DRracer/Arduino_Boards/master/IDE_Board_Manager/prusa3drambo-1.0.1.tar.bz2"
+BOARD_FILE_URL="https://raw.githubusercontent.com/prusa3d/Arduino_Boards/master/IDE_Board_Manager/prusa3drambo-1.0.1.tar.bz2"
 PF_BUILD_FILE_URL="https://github.com/3d-gussner/PF-build-env/releases/download/$BUILD_ENV/PF-build-env-$BUILD_ENV.zip"
 LIB="PrusaLibrary"
 SCRIPT_PATH="$( cd "$(dirname "$0")" ; pwd -P )"