Fix the compatible IIS versions

At installer file the IIS 6 was considered supported, however, it is
not supported. Supported IIS versions are 7 and 8.

Author: Felipe Zimmerle

iis/installer.wxs

@@ -88,7 +88,7 @@
             <RegistrySearch Id="FindInetPubFolder" Root="HKLM" Key="SOFTWARE\Microsoft\InetStp" Name="PathWWWRoot" Type="directory" />
         </Property>
         <Property Id="MSIUSEREALADMINDETECTION" Value="1" />
-        <Condition Message="This setup requires IIS 6.0, 7.0 or 8.0 is installed."><![CDATA[(IIS="#7") OR (IIS="#6") OR (IIS="#8")]]></Condition>
+        <Condition Message="This setup requires IIS 7.0 or 8.0."><![CDATA[(IIS="#7") OR (IIS="#8")]]></Condition>
         <!-- Version 2.7.5 had an uninstall issue that leaves some files behind. Asking the user to manually hash this out. -->
         <Condition Message="A older version of ModSecurityIIS was found in your computer. Please complete uninstall by removing the following file: [FILEEXISTS]. You may have to remove ModSecurity module from IIS, use the IIS Manager to do so."><![CDATA[(NOT FILEEXISTS) OR (Installed)]]></Condition>
         <Condition Message="64-bit operating system was detected, please use the 64-bit installer.">