DOCSP-5650: Improve misleading line in the Compose and mLab migration guides (#124)

Author: steveren

source/includes/steps-migrate-compose.yaml

@@ -144,9 +144,6 @@ content: |
   closes and you are returned to the Atlas cluster overview page. A
   progress bar shows the progess of your migration.
 
-  Once the migration is complete, you can begin to update your
-  client applications to use the new Atlas connection string.
-
   .. figure:: /images/migration-complete.png
      :figwidth: 700px
 ---
@@ -161,4 +158,8 @@ content: |
 
   Click the green :guilabel:`Start cutover` button and follow the
   instructions listed in the dialog window.
+
+  Once the cutover is complete, you can update your
+  client applications to use the new Atlas connection string.
+
 ...

source/includes/steps-migrate-mlab.yaml

@@ -176,9 +176,6 @@ content: |
   closes and you are returned to the Atlas cluster overview page. A
   progress bar shows the progess of your migration.
 
-  Once the migration is complete, you can begin to update your
-  client applications to use the new Atlas connection string.
-
   .. figure:: /images/migration-complete.png
      :figwidth: 700px
 ---
@@ -193,4 +190,7 @@ content: |
 
   Click the green :guilabel:`Start cutover` button and follow the
   instructions listed in the dialog window.
+
+  Once the cutover is complete, you can update your
+  client applications to use the new Atlas connection string.
 ...