reverse trim/lowercase change for now

Author: SachaG

lib/config/at_config.js

@@ -10,9 +10,7 @@ AccountsTemplates.addField({
     displayName: 'username',
     required: true,
     minLength: 3,
-    errStr: 'error.minChar',
-    trim: true,
-    lowercase: true
+    errStr: 'error.minChar'
 });
 
 AccountsTemplates.removeField('email');