minor clean up

Author: hathach

build_platform.py

@@ -63,12 +63,12 @@
 CHECK = u'\N{check mark}'
 
 BSP_URLS = (
-    "https://adafruit.github.io/arduino-board-index/package_adafruit_index.json"
-    ",http://arduino.esp8266.com/stable/package_esp8266com_index.json"
-    ",https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_dev_index.json"
-    ",https://sandeepmistry.github.io/arduino-nRF5/package_nRF5_boards_index.json"
-    ",https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json"
-    ",https://drazzy.good-enough.cloud/package_drazzy.com_index.json"
+    "https://adafruit.github.io/arduino-board-index/package_adafruit_index.json,"
+    "http://arduino.esp8266.com/stable/package_esp8266com_index.json,"
+    "https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_dev_index.json,"
+    "https://sandeepmistry.github.io/arduino-nRF5/package_nRF5_boards_index.json,"
+    "https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json,"
+    "https://drazzy.good-enough.cloud/package_drazzy.com_index.json"
 )
 
 # global exit code