[debug] change the dgetc signature to match external sources
diff --git a/include/debug.h b/include/debug.h
index e5ebc19..2944cb7 100644
--- a/include/debug.h
+++ b/include/debug.h
@@ -57,7 +57,7 @@
 #define dvprintf(level, x...) do { if ((level) <= DEBUGLEVEL) { _dvprintf(x); } } while (0)
 
 /* input */
-int dgetc(char *c);
+int dgetc(char *c, bool wait);
 
 /* systemwide halts */
 void halt(void) __NO_RETURN;