json-c: fix compile

package/json-c/patches/patch-Makefile_in

@@ -0,0 +1,11 @@
+--- json-c-0.12.1.orig/Makefile.in	2016-06-07 05:36:51.000000000 +0200
++++ json-c-0.12.1/Makefile.in	2017-06-06 02:16:08.632880056 +0200
+@@ -389,7 +389,7 @@ target_alias = @target_alias@
+ top_build_prefix = @top_build_prefix@
+ top_builddir = @top_builddir@
+ top_srcdir = @top_srcdir@
+-AM_CFLAGS = -Wall -Werror -Wno-error=deprecated-declarations -Wextra -Wwrite-strings -Wno-unused-parameter -std=gnu99 -D_GNU_SOURCE -D_REENTRANT
++AM_CFLAGS = -Wall -Wno-error=deprecated-declarations -Wextra -Wwrite-strings -Wno-unused-parameter -std=gnu99 -D_GNU_SOURCE -D_REENTRANT
+ EXTRA_DIST = README.html README-WIN32.html config.h.win32 doc json-c.vcproj
+ SUBDIRS = . tests
+ lib_LTLIBRARIES = libjson-c.la