Build jsondac with lower warning levels

json-c uses some macros that result in warnings that get thrown in
jsondacor.  We don't really care about warnings in the test library, so
set the warning level to 2.

Change-Id: I9bcb828d2545b51488f17a8545898c98d1164d09
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/tests/meson.build b/tests/meson.build
index 8101587..f5baef2 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,6 +1,6 @@
 jsonc_daccord = dependency(
     'jsoncdac',
-    default_options: ['default_library=static'],
+    default_options: ['default_library=static', 'warning_level=2'],
 )
 
 test_sources = files('base64_test.c', 'test-utils.c')