Update `check_requirements()` multiple string (#9356)

utils/general.py

@@ -363,7 +363,7 @@ def check_requirements(requirements=ROOT / 'requirements.txt', exclude=(), insta
             n += 1
 
     if s and install and AUTOINSTALL:  # check environment variable
-        LOGGER.info(f"{prefix} YOLOv5 requirements {s}not found, attempting AutoUpdate...")
+        LOGGER.info(f"{prefix} YOLOv5 requirement{'s' * (n > 1)} {s}not found, attempting AutoUpdate...")
         try:
             assert check_online(), "AutoUpdate skipped (offline)"
             LOGGER.info(check_output(f'pip install {s} {cmds}', shell=True).decode())