fix a typo in the man page

thanks dfc


svn:r2224

doc/tor.1.in

@@ -69,7 +69,7 @@ A list of preferred nodes to use for the first hop in the circuit, if possible.
 \fBexitnodes \fR\fInickname,nickname,...\fP
 A list of preferred nodes to use for the last hop in the circuit, if possible.
 .TP
-\fBexcludenodes \fR\iInickname,nickname,...\fP
+\fBexcludenodes \fR\fInickname,nickname,...\fP
 A list of nodes to never use when building a circuit.
 .TP
 \fBnewcircuitperiod \fR\fINUM\fP