Properly process condition_provider_uris configuration entry which can only be stored in the json configuration file as dictionary keyed by the string version of chain id.

The chain id is only stored in the configuration file as a string even though it is used in python as an integer.
When the UrsulaConfiguration is serialized to json the integer (chain id) is automatically stringified to be valid json. Therefore, when deserializing the configuration i.e. reading it in, chain must be read in as a string first then converted to integer.

nucypher/config/characters.py

@@ -36,7 +36,7 @@ class UrsulaConfiguration(CharacterConfiguration):
         keystore_path: Optional[Path] = None,
         rest_port: Optional[int] = None,
         certificate: Optional[Certificate] = None,
-        condition_provider_uris: Optional[Dict[int, List[str]]] = None,
+        condition_provider_uris: Optional[Dict[str, List[str]]] = None,
         *args,
         **kwargs,
     ) -> None:
@@ -58,7 +58,14 @@ class UrsulaConfiguration(CharacterConfiguration):
         super().__init__(
             dev_mode=dev_mode, keystore_path=keystore_path, *args, **kwargs
         )
-        self.condition_provider_uris = condition_provider_uris or dict()
+
+        # json configurations don't allow for integer keyed dictionaries
+        # so convert string chain id to integer
+        self.condition_provider_uris = dict()
+        if condition_provider_uris:
+            for chain, providers in condition_provider_uris.items():
+                # convert chain from string key (for json) to integer
+                self.condition_provider_uris[int(chain)] = providers
         self.configure_condition_provider_uris()
 
     def configure_condition_provider_uris(self) -> None:
@@ -68,11 +75,21 @@ class UrsulaConfiguration(CharacterConfiguration):
         polygon_chain_id = NetworksInventory.get_polygon_chain_id(
             self.pre_payment_network
         )
-        self.condition_provider_uris[polygon_chain_id] = [self.pre_payment_provider]
+        polygon_provider_uris = self.condition_provider_uris.get(polygon_chain_id, [])
+        if not polygon_provider_uris:
+            self.condition_provider_uris[polygon_chain_id] = polygon_provider_uris
+
+        if self.pre_payment_provider not in polygon_provider_uris:
+            polygon_provider_uris.append(self.pre_payment_provider)
 
         # Ethereum
         staking_chain_id = NetworksInventory.get_ethereum_chain_id(self.domain)
-        self.condition_provider_uris[staking_chain_id] = [self.eth_provider_uri]
+        staking_provider_uris = self.condition_provider_uris.get(staking_chain_id, [])
+        if not staking_provider_uris:
+            self.condition_provider_uris[staking_chain_id] = staking_provider_uris
+
+        if self.eth_provider_uri not in staking_provider_uris:
+            staking_provider_uris.append(self.eth_provider_uri)
 
     @classmethod
     def address_from_filepath(cls, filepath: Path) -> str: