Turned file path fields in Security BaseModel to Optional[Path]

Author: tieneupin

src/murfey/util/config.py

@@ -83,8 +83,7 @@ def from_file(config_file_path: Path, instrument: str = "") -> Dict[str, Machine
 
 
 class Security(BaseModel):
-    rabbitmq_credentials: str
-    murfey_db_credentials: str
+    murfey_db_credentials: Optional[Path] = None
     crypto_key: str
     auth_key: str = ""
     auth_algorithm: str = ""
@@ -94,10 +93,11 @@ class Security(BaseModel):
     session_token_timeout: Optional[int] = None
     auth_type: Literal["password", "cookie"] = "password"
     cookie_key: str = ""
+    rabbitmq_credentials: Optional[Path] = None
     feedback_queue: str = "murfey_feedback"
     graylog_host: str = ""
     graylog_port: Optional[int] = None
-    ispyb_credentials: str = ""
+    ispyb_credentials: Optional[Path] = None
 
     @validator("graylog_port")
     def check_port_present_if_host_is(