fix(docs): added info about SVN re-config when moving to Docker

docs/source/migration/migration-to-docker.rst

@@ -300,7 +300,21 b' be also adjusted in the UI'
     Session().add(ui3);Session().commit()
 
 
-11. Run full remap & rescan
+12. Adjust SVN Proxy
+++++++++++++++++++++
+
+.. note::
+
+    This is only required for pre 5.1 migration, if you're migrating from 4.X to 5.1+ this step can be omitted.
+
+Go to the VCS config from the :menuselection:`Admin --> Settings --> VCS
+
+- Select Proxy subversion HTTP requests checkbox
+- Enter http://svn:8090 into Subversion HTTP Server URL
+- Click the Generate Apache Config button.
+
+
+13. Run full remap & rescan
 +++++++++++++++++++++++++++
 
 From RhodeCode web-interface, the last step is to run a full remap & rescan action.