Fix bug 1593 - Can not create Openstack vim due to special characters in username

I've checked the code in common and in NBI to see if there was a
possible vector for NoSQL Injection and there wasn't.

Change-Id: I9f1626f8d943999d94d82444aec12efa0f66ddc7
Signed-off-by: sousaedu <eduardo.sousa@canonical.com>
diff --git a/osm_nbi/validation.py b/osm_nbi/validation.py
index de8f913..9bc2624 100644
--- a/osm_nbi/validation.py
+++ b/osm_nbi/validation.py
@@ -448,7 +448,7 @@
         # "vim_url_admin": description_schema,
         # "vim_tenant": name_schema,
         "vim_tenant_name": name_schema,
-        "vim_user": shortname_schema,
+        "vim_user": string_schema,
         "vim_password": passwd_schema,
         "config": {"type": "object"}
     },
@@ -471,7 +471,7 @@
         # "vim_url_admin": description_schema,
         # "vim_tenant": name_schema,
         "vim_tenant_name": name_schema,
-        "vim_user": shortname_schema,
+        "vim_user": string_schema,
         "vim_password": passwd_schema,
         "config": {"type": "object"}
     },