Fix incorrect boostification of #warning message.

asio/boostify.pl

diff --git a/asio/boostify.pl b/asio/boostify.pl
index 1beadd0..4ca2fbe 100755
--- a/asio/boostify.pl
+++ b/asio/boostify.pl
@@ -220,7 +220,7 @@
         print_line($output, $1 . "<boost/system/system_error.hpp>", $from, $lineno);
       }
     }
-    elsif ($line =~ /(^.*# *include )[<"](asio\/.*)[>"](.*)$/)
+    elsif ($line =~ /(^.*# *include )[<"](asio\/[^>"]*)[>"](.*)$/)
     {
       print_line($output, $1 . "<boost/" . $2 . ">" . $3, $from, $lineno);
     }