[json-c] always install pc files (#14086)

ports/json-c/CONTROL

@@ -1,4 +1,5 @@
 Source: json-c
 Version: 2019-09-10
+Port-Version: 1
 Description: A JSON implementation in C
 Homepage: https://github.com/json-c/json-c

ports/json-c/pkgconfig.patch

@@ -0,0 +1,13 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index ffb1db3dc..a82ed8619 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -273,7 +273,7 @@ install(
+     DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
+ )
+ 
+-if (UNIX OR MINGW OR CYGWIN)
++if (1)
+     SET(prefix ${CMAKE_INSTALL_PREFIX})
+     # exec_prefix is prefix by default and CMake does not have the
+     # concept.

ports/json-c/portfile.cmake

@@ -1,11 +1,10 @@
-include(vcpkg_common_functions)
-
 vcpkg_from_github(
     OUT_SOURCE_PATH SOURCE_PATH
     REPO json-c/json-c
     REF eae040a84a479ccad1d1c48314345c51ecf1a4a4
     SHA512 18d8a31b341830b04676cad13fbc0608fb75a323522161ac8fd0bb5058db82c1c261d504696a1e12f4b03eb0967632885580ff81d808adf2f1dff7e32d131ba0
     HEAD_REF master
+    PATCHES pkgconfig.patch
 )
 
 vcpkg_configure_cmake(
@@ -16,7 +15,7 @@ vcpkg_configure_cmake(
 vcpkg_install_cmake()
 
 vcpkg_fixup_cmake_targets(CONFIG_PATH lib/cmake/${PORT})
-
+vcpkg_fixup_pkgconfig()
 vcpkg_copy_pdbs()
 
 file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/include)