Revert "json.== handles nil now"

lib/pure/json.nim

@@ -621,13 +621,9 @@ proc `%`*(elements: openArray[PJsonNode]): PJsonNode =
 
 proc `==`* (a,b: PJsonNode): bool =
   ## Check two nodes for equality
-  if a.isNil:
+  if a.kind != b.kind: false
-    if b.isNil: return true
-    return false
-  elif b.isNil or a.kind != b.kind: 
-    return false
   else:
-    return case a.kind
+    case a.kind
     of JString:
       a.str == b.str
     of JInt: