Update startup script to remove stale PHP-FPM pid files.

setup/resources/wsl/startup.sh

@@ -5,6 +5,20 @@ if [[ $(id -u) -ne 0 ]]; then
   exit 1
 fi
 
+# If PHP-FPM wasn't stopped properly, its .pid file will still exist. When
+# restarting the service, it will get stuck if a stale .pid file exists.
+# Remove the stale existing .pid files so the restart won't get stuck.
+for file in `find /opt/phpenv/versions -name "*.pid"`
+do
+  PHPFPM_PID=$(cat $file)
+  PID_CMD=$(ps -p $PHPFPM_PID -o comm=)
+
+  if [[ "$PID_CMD" != "php-fpm" ]]; then
+    echo "Removing stale pid file [$file]."
+    rm -f $file
+  fi
+done
+
 service redis-server restart
 service mysql restart
 service apache2 restart