[chore] correct kafka offset attribute name in kafka sample (#1929)

Co-authored-by: Armin Ruech <7052238+arminru@users.noreply.github.com>

Author: Flarna

docs/messaging/kafka.md

@@ -207,6 +207,6 @@ flowchart LR;
 | `messaging.operation.type` | `"send"`  | `"receive"` | `"process"` | `"settle"` |
 | `messaging.client.id` | `"5"` | `"8"` | `"8"` | `"8"` |
 | `messaging.kafka.message.key` | `"myKey"` | `"myKey"` | `"myKey"` |  |
-| `messaging.kafka.message.offset` |  | `"12"` | `"12"` | `"12"` |
+| `messaging.kafka.offset` |  | `"12"` | `"12"` | `"12"` |
 
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