stream-cast.xml Fix typo (#4961)

Author: mmalferov

reference/stream/streamwrapper/stream-cast.xml

@@ -4,7 +4,7 @@
 <refentry xml:id="streamwrapper.stream-cast" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
  <refnamediv>
   <refname>streamWrapper::stream_cast</refname>
-  <refpurpose>Retrieve the underlaying resource</refpurpose>
+  <refpurpose>Retrieve the underlying resource</refpurpose>
  </refnamediv>
 
  <refsect1 role="description">