zh_CN: fix a mistake in hostreq

Thanks fyang.168.hi's report.

zh_CN/chapter02/hostreqs.po

@@ -64,9 +64,7 @@ msgstr ""
 
 #. type: Content of: <sect1><itemizedlist><listitem><para>
 msgid "<emphasis role=\"strong\">Bzip2-1.0.4</emphasis>"
-msgstr ""
-"<emphasis role=\"strong\">Bison-2.7</emphasis> (/usr/bin/yacc 必须是到 bison "
-"的链接，或者是一个执行 bison 的小脚本)"
+msgstr "<emphasis role=\"strong\">Bzip2-1.0.4</emphasis>"
 
 #. type: Content of: <sect1><itemizedlist><listitem><para>
 msgid "<emphasis role=\"strong\">Coreutils-6.9</emphasis>"