fix: change default base port from 5052 to 8081 in converter

The assumption that all clients use port 5052 is incorrect.
Update to use 8081 as the default base port, which matches
the metricsPort values in validator-config.yaml.

Author: ch4r10t33r

convert-validator-config.py

@@ -20,7 +20,7 @@
 import yaml
 
 
-def convert_validator_config(yaml_path: str, output_path: str, base_port: int = 5052):
+def convert_validator_config(yaml_path: str, output_path: str, base_port: int = 8081):
     """
     Convert validator-config.yaml to upstreams.json.