Centralize user_config_dir() decision making (#4755)

utils/plots.py

@@ -4,7 +4,6 @@ Plotting utils
 """
 
 import math
-import os
 from copy import copy
 from pathlib import Path
 
@@ -21,7 +20,7 @@ from utils.general import user_config_dir, is_ascii, xywh2xyxy, xyxy2xywh
 from utils.metrics import fitness
 
 # Settings
-CONFIG_DIR = Path(os.getenv('YOLOV5_CONFIG_DIR') or user_config_dir())  # Ultralytics settings dir
+CONFIG_DIR = user_config_dir()  # Ultralytics settings dir
 matplotlib.rc('font', **{'size': 11})
 matplotlib.use('Agg')  # for writing to files only