Escape literal asterisk.

README

@@ -35,7 +35,7 @@ Some parsing performance figures:
 On a 2.3Ghz Corei5, apachedex achieves 97000 lines/s (
 pypy-c-jit-62994-bd32583a3f11-linux64) and 43000 lines/s (CPython 2.7).
 Those were measures on a 3000000-hits logfile, with 3 --skip-base, 1
---erp5-base, 3 --base and --default set. --*base values were similar in
+--erp5-base, 3 --base and --default set. --\*base values were similar in
 simplicity to the ones provided in examples below.
 
 What APacheDEX is not