Tests: handle case when no OpenCL device is available

Author: howetuft

python/pyluxcoretest/pyluxcoretest.py

@@ -161,7 +161,10 @@ def PropertiesTests():
 
 def LuxRaysDeviceTests():
     print("LuxRays device information example......", flush=True)
-    deviceList = pyluxcore.GetOpenCLDeviceList()
+    try:
+        deviceList = pyluxcore.GetOpenCLDeviceList()
+    except RuntimeError as err:
+        print(str(err))
     print("OpenCL device list: %s\n" % str(deviceList), flush=True)