Fixing some potential upgrade issues and two issues found with the legacy member API

- For legacy API we never had and "approved" checkbox, so the assumption is that members are always approved
- The RequiresUniqueEmail check was wrong, previously the assumption was: if there's no e-mail then don't check for uniqueness

src/Umbraco.Web.UI/web.Template.Release.config

@@ -23,6 +23,16 @@
     <trace enabled="false" xdt:Transform="SetAttributes(enabled)" />
     <customErrors mode="RemoteOnly" xdt:Transform="SetAttributes(mode)">
     </customErrors>
+
+    <membership>
+      <providers>
+        <add xdt:Transform="SetAttributes(useLegacyEncoding)" xdt:Locator="Match(name)" name="UmbracoMembershipProvider" 
+              useLegacyEncoding="true" />
+        <add xdt:Transform="SetAttributes(useLegacyEncoding)" xdt:Locator="Match(name)" name="UsersMembershipProvider" 
+             useLegacyEncoding="true" />
+      </providers>
+    </membership>
   </system.web>
 
+
 </configuration>