Update start.py

replace /var/log/nginx.pid with /var/run/nginx.pid to ensure consistency with core/nginx/conf/nginx.conf

core/nginx/start.py

@@ -4,8 +4,8 @@ import os
 import subprocess
 
 # Check if a stale pid file exists
-if os.path.exists("/var/log/nginx.pid"):
+if os.path.exists("/var/run/nginx.pid"):
-    os.remove("/var/log/nginx.pid")
+    os.remove("/var/run/nginx.pid")
 
 if os.environ["TLS_FLAVOR"] in [ "letsencrypt","mail-letsencrypt" ]:
     subprocess.Popen(["/letsencrypt.py"])