Only register exit function if a PID file was created

The function only deletes the PID file.

radicale/__main__.py

@@ -116,7 +116,6 @@ def run():
 
 def daemonize(configuration, logger):
     """Fork and decouple if Radicale is configured as daemon."""
-    if configuration.getboolean("server", "daemon"):
     # Check and create PID file in a race-free manner
     if configuration.get("server", "pid"):
         try:
@@ -136,6 +135,14 @@ def daemonize(configuration, logger):
         sys.exit()
     if configuration.get("server", "pid"):
         os.close(pid_fd)
+
+        # Register exit function
+        def cleanup():
+            """Remove the PID files."""
+            logger.debug("Cleaning up")
+            # Remove PID file
+            os.unlink(pid_path)
+        atexit.register(cleanup)
     # Decouple environment
     os.chdir("/")
     os.setsid()
@@ -145,17 +152,6 @@ def daemonize(configuration, logger):
         os.dup2(null_out.fileno(), sys.stdout.fileno())
         os.dup2(null_out.fileno(), sys.stderr.fileno())
 
-    # Register exit function
-    def cleanup():
-        """Remove the PID files."""
-        logger.debug("Cleaning up")
-        # Remove PID file
-        if (configuration.get("server", "pid") and
-                configuration.getboolean("server", "daemon")):
-            os.unlink(pid_path)
-
-    atexit.register(cleanup)
-
 
 def serve(configuration, logger):
     """Serve radicale from configuration."""
@@ -234,6 +230,7 @@ def serve(configuration, logger):
     else:
         # Fallback to busy waiting
         select_timeout = 1.0
+    if configuration.getboolean("server", "daemon"):
         daemonize(configuration, logger)
     logger.debug("Radicale server ready")
     while not shutdown_program: