contrib: homogeneize jsoncpp versions across platforms

Seems that JSONcpp symbols changed between 1.7.4/1.7.6 causing
some versions to fail.
We already uses 1.9.3 since a long time on other platforms
and ubuntu 22 got a version recent enough too.

Change-Id: I21a4c44ee1359a7d89e45770cb2bad9f2eb00cce
GitLab: #824

contrib/src/jsoncpp/rules.mak

 # JSONCPP
-ifdef HAVE_ANDROID
 JSONCPP_VERSION := 1.9.3
-else
-ifdef HAVE_LINUX
-JSONCPP_VERSION := 1.7.2
-else
-JSONCPP_VERSION := 1.9.3
-endif
-endif
 
 JSONCPP_URL := https://github.com/open-source-parsers/jsoncpp/archive/$(JSONCPP_VERSION).tar.gz
 
 PKGS += jsoncpp
 
-ifeq ($(call need_pkg,"jsoncpp >= 1.7.2"),)
+ifeq ($(call need_pkg,"jsoncpp >= 1.9.3"),)
 PKGS_FOUND += jsoncpp
 endif