Fix building aws_key_management on Linux

in MYSQL_ADD_PLUGIN, do not add TARGET_LINK_LIBRARIES twice for the LINK_LIBRARIES parameter
It is usually harmless to add libraries twice.

However, aws_key_management uses -Wl,-whole-archive to workaround linker issues on Linux
If libraries are added twice with whole-archive, linking will fail complaining about duplicate symbols

cmake/plugin.cmake

@@ -210,9 +210,6 @@ MACRO(MYSQL_ADD_PLUGIN)
       ENDIF()
     ENDIF()
 
-    IF(ARG_LINK_LIBRARIES)
-      TARGET_LINK_LIBRARIES (${target} ${ARG_LINK_LIBRARIES})
-    ENDIF()
     ADD_DEPENDENCIES(${target} GenError ${ARG_DEPENDENCIES})
 
     SET_TARGET_PROPERTIES(${target} PROPERTIES