Warn if the development environment is not found

SRC/contrib/adamsnames/configure.ac

@@ -10,6 +10,8 @@ AC_CHECK_PROG(ADAMSNAMES_BUILD, xmlrpc-c-config, 1, 0)
 if test "$ADAMSNAMES_BUILD" = 1; then
    LIBS="${LIBS} `xmlrpc-c-config libwww-client --libs`"
    CCFLAGS="${CCFLAGS} `xmlrpc-c-config libwww-client --cflags`"
+else
+   AC_ERROR([No XML-RPC C developement environment found, get it from http://xmlrpc-c.sourceforge.net/])
 fi
 AM_CONDITIONAL(ADAMSNAMESBUILD, test "$ADAMSNAMES_BUILD" = 1)
 AC_OUTPUT(Makefile)