logger: smal fix

Author: josephjclark

.changeset/humble-ravens-send.md

@@ -0,0 +1,5 @@
+---
+'@openfn/logger': patch
+---
+
+Fix an issue where logger.proxy can throw for nil values

packages/logger/src/logger.ts

@@ -262,6 +262,8 @@ export default function (name?: string, options: LogOptions = {}): Logger {
     }
     j = j as JSONLog;
 
+    j.message ??= [];
+
     log(j.name, j.level, ...j.message);
     return [j.name, j.level, ...j.message];
   };