在装php时出现以下的错误：
/root/Downloads/php-5.6.5/ext/xmlrpc/libxmlrpc/encodings.c:73: undefined reference to `libiconv_open'
/root/Downloads/php-5.6.5/ext/xmlrpc/libxmlrpc/encodings.c:81: undefined reference to `libiconv'
/root/Downloads/php-5.6.5/ext/xmlrpc/libxmlrpc/encodings.c:101: un[……]
