chapter03: Fix "NaN MB" in package list page

The stylesheet doesn't support "5.1 MB".  Change openssl-size to
"5,278 KB".

packages.ent

@@ -513,7 +513,7 @@
 <!ENTITY ninja-ch6-sbu "0.2 SBU">
 
 <!ENTITY openssl-version "1.1.0g">
-<!ENTITY openssl-size "5.1 MB">
+<!ENTITY openssl-size "5,278 KB">
 <!ENTITY openssl-url "https://openssl.org/source/openssl-&openssl-version;.tar.gz">
 <!ENTITY openssl-md5 "ba5f1b8b835b88cadbce9b35ed9531a6">
 <!ENTITY openssl-home "https://www.openssl.org/">