1- Add the  following settings in the httpd.conf file: 

• For releases of IBM HTTP Server V1.3.12, 1.3.19, 1.3.26, 1.3.28:

LoadModule rewrite_module    libexec/mod_rewrite.so
AddModule mod_rewrite.c

• For releases of IBM HTTP Server V2.0x, 6.0x, 6.1x and 7.0x:   

LoadModule rewrite_module    modules/mod_rewrite.so

2-Add following global scope for any 80 port :

RewriteEngine on
RewriteCond %{SERVER_PORT} =80
RewriteRule ^(.*) https://}%{SERVER_NAME}%{REQUEST_URI

3- If you use Plugin , remove 80 port from virtual hosts configuration.