fix B16005 engraving headstone with weapon

>If you're engraving one with a weapon, shouldn't it dull that
>	weapon?

doc/fixes34.1

@@ -358,6 +358,7 @@ prevent recoil from hurtling you through narrow areas that you wouldn't
 grammar in cause of death when killed by slipping while mounting named steed
 ensure `m'enu is still an available traditional menu choice for 
 	menu-upon-request even when there is only one class of object present
+engraving on headstone will appropriately dull your weapon
 
 
 Platform- and/or Interface-Specific Fixes

src/engrave.c

@@ -1017,6 +1017,7 @@ doengrave()
 		multi = -(len/10);
 		if (multi) nomovemsg = "You finish writing in the dust.";
 		break;
+	    case HEADSTONE:
 	    case ENGRAVE:
 		multi = -(len/10);
 		if ((otmp->oclass == WEAPON_CLASS) &&