refactor(statuspal): improve import of flatdict

Author: markuslf

check-plugins/statuspal/statuspal

@@ -14,7 +14,6 @@
 import argparse  # pylint: disable=C0413
 import json  # pylint: disable=C0413
 import sys  # pylint: disable=C0413
-import flatdict  # pylint: disable=C0413
 
 import lib.args  # pylint: disable=C0413
 import lib.base  # pylint: disable=C0413
@@ -25,8 +24,15 @@ import lib.url  # pylint: disable=C0413
 from lib.globals import (STATE_CRIT, STATE_OK,  # pylint: disable=C0413
                           STATE_UNKNOWN, STATE_WARN)
 
+try:
+    import flatdict  # pylint: disable=C0413
+except ImportError as e:
+    print('Python module "flatdict" is not installed.')
+    sys.exit(STATE_UNKNOWN)
+
+
 __author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
-__version__ = '2025021501'
+__version__ = '2025030601'
 
 DESCRIPTION = """Statuspal is a status page provider from Germany. This check plugin gets
                  the summary of a Statuspal status page, checks its status, services,