SSI Web v7 is no longer formally supported, but you can probably change this behavior by modifying your installation files. Where you installed SSI Web, locate the file authlib7_0_30.pl. You may want to make a backup of this file before changing it, but you can always get it back again by reinstalling SSI Web.
Locate and remove this from the contents of that file:
$__aqy .= "<meta http-equiv=\"X-UA-Compatible\" content=\"IE=EmulateIE7\">\n\n";
Note that this will not affect the behavior when running Test Survey. You will need to upload your study to verify the fix.