wtf??! it suddenly worked.. did nothing at all and the redirection starded to work. good for me^^
Code:
pass in on $int_if proto tcp from $int_net to $ext_if port { http, https } \
rdr-to $wwwserver
pass out on $int_if proto tcp to $wwwserver port { http, https } \
received-on $int_if nat-to $int_if