SetEnvIfNoCase Content-Type ^(multipart/)(form-data)(\s*;\s*.*)$ NEWCT=$1shopfusion-$2$3 OLDCT=$1$2$3
RewriteCond %{QUERY_STRING} \bSFFORM\b [NC]
RewriteCond %{ENV:NEWCT} shopfusion [NC]
RewriteRule (.*) - [E=APPLYNEWCT:1]
RequestHeader set Content-Type %{NEWCT}e env=APPLYNEWCT