Make conditions easier to read

Combining both the inline and "traditional" `if` styles made the code
difficult to read, particularly when compiled to JavaScript.

app/assets/javascripts/budget_edit_associations.js.coffee

@@ -20,5 +20,5 @@ App.BudgetEditAssociations =
       click: ->
         div_id = $(this).data().toggle
         $(".js-budget-users-list").each ->
-          if this.id != div_id
-            $(this).addClass("is-hidden") if !$(this).hasClass("is-hidden")
+          if this.id != div_id && !$(this).hasClass("is-hidden")
+            $(this).addClass("is-hidden")