Fix build of jsoncpp. am: 70fddb61d1 am: 94f53395ef am: e1c1d65a2b

Original change: https://android-review.googlesource.com/c/platform/tools/ndkports/+/1231408

Change-Id: I647d2366655a19d17ccf4dc8cf3940d4c2d73b7d