fix(azure): normalize host field (#662)

It seems that Azure EventHub sends host information as "Host". This doesn't comply with Datadog's conventions so the host is not show in the log explorer.

This detects if the Host field exists and adds the lower case host variant.

---------

Co-authored-by: Ava Silver <ava.silver@datadoghq.com>

Author: robertohuertasm

azure/activity_logs_monitoring/index.js

@@ -5,7 +5,7 @@
 
 var https = require('https');
 
-const VERSION = '1.0.1';
+const VERSION = '1.0.2';
 
 const STRING = 'string'; // example: 'some message'
 const STRING_ARRAY = 'string-array'; // example: ['one message', 'two message', ...]
@@ -311,6 +311,10 @@ class EventhubLogHandler {
     formatLog(messageType, record) {
         if (messageType == JSON_TYPE) {
             var originalRecord = this.addTagsToJsonLog(record);
+            // normalize the host field. Azure EventHub sends it as "Host".
+            if (originalRecord.Host) {
+                originalRecord.host = originalRecord.Host;
+            }
             var source = originalRecord['ddsource'];
             var config = this.logSplittingConfig[source];
             if (config !== undefined) {