revert kill_xp updates removal to preserve functionality of in-repo mods

Author: KamikazieBoater

src/kill_tracker.cpp

@@ -104,6 +104,9 @@ static Character *get_avatar_or_follower( const character_id &id )
     return nullptr;
 }
 
+// Legacy value, maintained until kill_xp rework/removal from dependent in-repo mods
+static constexpr int npc_kill_xp = 10;
+
 void kill_tracker::notify( const cata::event &e )
 {
     switch( e.type() ) {
@@ -112,6 +115,8 @@ void kill_tracker::notify( const cata::event &e )
             if( Character *killer = get_avatar_or_follower( killer_id ) ) {
                 const mtype_id victim_type = e.get<mtype_id>( "victim_type" );
                 kills[victim_type]++;
+                // Legacy value update, maintained until kill_xp rework/removal from dependent in-repo mods
+                killer->kill_xp += e.get<int>( "exp" );
                 victim_type.obj().families.practice_kill( *killer );
             }
             break;
@@ -122,6 +127,8 @@ void kill_tracker::notify( const cata::event &e )
             if( get_avatar_or_follower( killer_id ) ) {
                 const std::string victim_name = e.get<cata_variant_type::string>( "victim_name" );
                 npc_kills.push_back( victim_name );
+                // Legacy value update, maintained until kill_xp rework/removal from dependent in-repo mods
+                killer->kill_xp += npc_kill_xp;
             }
             break;
         }