fixup hint in Flux v1 Migration guide

The wrong indenting means the hint body will not display as a hint

Signed-off-by: Kingdon Barrett <kingdon@weave.works>

docs/guides/flux-v1-automation-migration.md

@@ -431,8 +431,8 @@ spec:
 ```
 
 !!! hint
-  If you are using the same image repository in several manifests, you only need one
+    If you are using the same image repository in several manifests, you only need one
-  `ImageRepository` object for it.
+    `ImageRepository` object for it.
 
 ##### Using image registry credentials for scanning