Revert soversion change -- unnecessary (#1667)

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0cc34c9..c1de7ae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -61,7 +61,7 @@
         LANGUAGES CXX)
 
 message(STATUS "JsonCpp Version: ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT_VERSION_PATCH}")
-set(PROJECT_SOVERSION 28)
+set(PROJECT_SOVERSION 27)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/include/PreventInSourceBuilds.cmake)
 include(${CMAKE_CURRENT_SOURCE_DIR}/include/PreventInBuildInstalls.cmake)

meson.build

diff --git a/meson.build b/meson.build
index efcbaa4..e08314b 100644
--- a/meson.build
+++ b/meson.build
@@ -51,7 +51,7 @@
     'src/lib_json/json_value.cpp',
     'src/lib_json/json_writer.cpp',
   ]),
-  soversion : 28,
+  soversion : 27,
   install : true,
   include_directories : jsoncpp_include_directories,
   cpp_args: dll_export_flag)