try allow missing message in logs

Author: tanmaykm

src/jobs/logging-legacy.jl

@@ -1,7 +1,7 @@
 struct _LegacyLogging <: _JobLoggingAPIVersion end
 
 function JobLogMessage(::_LegacyLogging, json::Dict, offset::Integer)
-    message = _get_json(json, "message", String)
+    message = _get_json_or(json, "message", String, "")
     keywords = _get_json_or(json, "keywords", Dict, Dict{String, Any}())
     metadata = _get_json_or(json, "metadata", Dict, Dict{String, Any}())
     timestamp = if haskey(json, "timestamp")