installer: really default to Secure Channel

Commit 8a7ab99 (installer: switch the libcurl default to Secure Channel,
2023-05-15) attempted to change the default libcurl backend for clean
new installs to Secure channel, but only adjusted one of two fallbacks
in the installer. There is one default value that gets passed to
ReplayChoice() to return if it finds no previous choice and one value
that gets used if ReplayChoice() returns an unexpected value. 8a7ab99
changed the latter to use Secure Channel, but left the former to default
to OpenSSL. Adjust the default value to match the intention of that
patch.

This fixes git-for-windows/git#5295

Signed-off-by: Matthias Aßhauer <[email protected]>

installer/install.iss

@@ -2324,7 +2324,7 @@ begin
     RdbCurlVariant[GC_WinSSL]:=CreateRadioButton(CurlVariantPage,'Use the native Windows Secure Channel library','Server certificates will be validated using Windows Certificate Stores.'+#13+'This option also allows you to use your company''s internal Root CA certificates'+#13+'distributed e.g. via Active Directory Domain Services.',TabOrder,Top,Left);
 
     // Restore the setting chosen during a previous install.
-    case ReplayChoice('CURL Option','OpenSSL') of
+    case ReplayChoice('CURL Option','WinSSL') of
         'OpenSSL': RdbCurlVariant[GC_OpenSSL].Checked:=True;
         'WinSSL': RdbCurlVariant[GC_WinSSL].Checked:=True;
     else