Fix table error (#4383)

Author: mowangjuanzi

reference/var/functions/unserialize.xml

@@ -158,6 +158,12 @@
    <informaltable>
     <tgroup cols="2">
      <thead>
+      <row>
+       <entry>&Version;</entry>
+       <entry>&Description;</entry>
+      </row>
+     </thead>
+     <tbody>
       <row>
        <entry>8.4.0</entry>
        <entry>
@@ -166,12 +172,6 @@
         element of <parameter>options</parameter> is not an <type>array</type> of class names.
        </entry>
       </row>
-      <row>
-       <entry>&Version;</entry>
-       <entry>&Description;</entry>
-      </row>
-     </thead>
-     <tbody>
       <row>
        <entry>8.3.0</entry>
        <entry>