Fix typo in rds_instance docs for master_user_password (#1617)

Fix typo in rds_instance docs for master_user_password

SUMMARY

Fix typo in rds_instance docs for master_user_password attribute

ISSUE TYPE

Docs Pull Request

COMPONENT NAME

rds_instance
ADDITIONAL INFORMATION

Reviewed-by: Mark Chappell
Reviewed-by: Alina Buzachis
(cherry picked from commit a04109d)

plugins/modules/rds_instance.py

@@ -250,7 +250,7 @@
     master_user_password:
         description:
           - An 8-41 character password for the master database user. The password can contain any printable ASCII character
-            except C(/), C("), or C(@). To modify the password use I(force_update_password). Use I(apply immediately) to change
+            except C(/), C("), or C(@). To modify the password use I(force_update_password). Use I(apply_immediately) to change
             the password immediately, otherwise it is updated during the next maintenance window.
         aliases:
           - password