fix #M57 - alchemical potion explosion fails to wake monsters

From a bug report,
the message when dipping one stack of potions into another triggers an
explosion says "BOOM" yet nearby sleeping monsters remained undisturbed.

doc/fixes34.4

@@ -368,6 +368,7 @@ cutting a long worm in half would trigger segfault/accvio crash if the hit
 blinded invisible hero can't see self as invisible via ';' or '/'
 a hangup save while picking up gold from shop floor could duplicate that gold
 jellyfish do not technically have a head
+potion explosion during failed alchemy should awaken nearby monsters
 
 
 Platform- and/or Interface-Specific Fixes

src/potion.c

@@ -1841,6 +1841,7 @@ dodip()
 		/* KMH, balance patch -- acid is particularly unstable */
 		if (obj->cursed || obj->otyp == POT_ACID || !rn2(10)) {
 			pline("BOOM!  They explode!");
+			wake_nearto(u.ux, u.uy, (BOLT_LIM+1)*(BOLT_LIM+1));
 			exercise(A_STR, FALSE);
 			if (!breathless(youmonst.data) || haseyes(youmonst.data))
 				potionbreathe(obj);