Add pvpAutoPause rule (#8249)

* Update Rules.java

* Update NetServer.java

core/src/mindustry/game/Rules.java

@@ -31,6 +31,8 @@ public class Rules{
     public boolean waves;
     /** Whether the game objective is PvP. Note that this enables automatic hosting. */
     public boolean pvp;
+    /** Whether is waiting for players enabled in PvP. */
+    public boolean pvpAutoPause = true;
     /** Whether to pause the wave timer until all enemies are destroyed. */
     public boolean waitEnemies = false;
     /** Determines if gamemode is attack mode. */