Fix spelling of "vacuum" in one of the abort quotes.

Author: jorendorff

src/libstd/rt/util.rs

@@ -116,7 +116,7 @@ weedy but not remembered; terrible spires and monoliths of lands that men never
 knew were lands...",
         4 => "
 There was a night when winds from unknown spaces whirled us irresistibly into
-limitless vacum beyond all thought and entity. Perceptions of the most
+limitless vacuum beyond all thought and entity. Perceptions of the most
 maddeningly untransmissible sort thronged upon us; perceptions of infinity
 which at the time convulsed us with joy, yet which are now partly lost to my
 memory and partly incapable of presentation to others.",