[skip-revcheck] Fix typo on dom-ns-import-simplexml (#4290)

Author: Fan2Shrek

reference/dom/functions/dom-ns-import-simplexml.xml

@@ -17,7 +17,7 @@
   <simpara>
    This function takes the given attribute or element <parameter>node</parameter> (a
    <classname>SimpleXMLElement</classname> instance) and creates a
-   <classname>Dom\Attr</classname> or <classname>Dom\Element</classname> node, repectively.
+   <classname>Dom\Attr</classname> or <classname>Dom\Element</classname> node, respectively.
    The new <classname>Dom\Node</classname> refers to the same underlying XML node
    as the <classname>SimpleXMLElement</classname>.
   </simpara>