Launcher script: added a catch for json decode errors

LaunchScript/VirtualAcousticsStarterServer.py

@@ -17,8 +17,12 @@ class ErrorCodes(Enum):
 # Class representing the VA-Launcher config (.json) file
 class LauncherConfig:
   def __init__(conf, sConfigFile):
+    try:
       with open( sConfigFile ) as json_file:
         json_config = json.load(json_file)
+    except Exception as e:
+      print( "ERROR reading the json config:" + os.linesep + str(e) )
+      sys.exit( ErrorCodes.ERROR_INCOMPLETE_CONFIG )
 
     try:
       conf.dVirtualAcousticDirectories = json_config["dVAServerDirectories"]