libxmlrpc: disable parallel build

Although upstream tries to support parallel builds, there are several
dependencies that, if fixed, would end up making the library build
linearly, so in the end there would be no benefit to fix those.

Fixes:

  http://autobuild.buildroot.net/results/996/996fc95b302fb6dfc7cd9a468fd395226a36c6c4/

Suggested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Alvaro G. M. <alvaro.gamez@hazent.com>
Signed-off-by: Alvaro G. M <alvaro.gamez@hazent.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libxmlrpc/libxmlrpc.mk

@@ -12,6 +12,7 @@ LIBXMLRPC_LICENSE_FILES = doc/COPYING
 LIBXMLRPC_INSTALL_STAGING = YES
 LIBXMLRPC_DEPENDENCIES = libcurl
 LIBXMLRPC_CONFIG_SCRIPTS = xmlrpc-c-config
+LIBXMLRPC_MAKE = $(MAKE1)
 
 LIBXMLRPC_CONF_OPT = \
 	$(if $(BR2_USE_WCHAR),,ac_cv_header_wchar_h=no) \