dispchar for oauth_client_secret

commit b3f0be7 wrote:
+    {"oauth_scope", NULL, NULL, NULL,
+        "OAuth-Scope", "", 15,
+    offsetof(struct pg_conn, oauth_scope)},

The field containing "" is documented as follows:

    char       *dispchar;        /* Indicates how to display this field in a
                                 * connect dialog. Values are: "" Display
                                 * entered value as is "*" Password field -
                                 * hide value "D"  Debug option - don't show
                                 * by default */

I suspect this should use .dispchar="*" to encourage UIs to display
oauth_client_secret like a password field.  Thoughts?

[I didn't review commit b3f0be7, but this caught my attention.]