nghttpd2: docs - update required libnghttp2 version

src/modules/nghttp2/doc/nghttp2_admin.xml

@@ -43,7 +43,7 @@
 			<itemizedlist>
 			<listitem>
 			<para>
-				<emphasis>libnghttp2</emphasis> - libnghttpd library (v1.61.0+)
+				<emphasis>libnghttp2</emphasis> - libnghttpd library (v1.43.0+)
 			</para>
 			</listitem>
 			</itemizedlist>