[skip-revcheck] Corrected spelling (#979)

Diffrent should be different.

Author: thisisboris

reference/stream/functions/stream-context-set-option.xml

@@ -42,7 +42,7 @@
      <term><parameter>wrapper</parameter></term>
      <listitem>
       <para>
-       The name of the wrapper (which may be diffrent than the protocol).
+       The name of the wrapper (which may be different than the protocol).
        Refer to <link linkend="context">context options and parameters</link>
        for a listing of stream options.
      </para>