configure: Added krb5 to the supported features

configure.ac

@@ -3368,6 +3368,11 @@ if test "x$CURL_DISABLE_CRYPTO_AUTH" != "x1" -a \
   SUPPORT_FEATURES="$SUPPORT_FEATURES SPNEGO"
 fi
 
+if test "x$CURL_DISABLE_CRYPTO_AUTH" != "x1" -a \
+    \( "x$USE_WINDOWS_SSPI" = "x1" \); then
+  SUPPORT_FEATURES="$SUPPORT_FEATURES krb5"
+fi
+
 if test "x$CURL_DISABLE_HTTP" != "x1" -a \
     "x$CURL_DISABLE_CRYPTO_AUTH" != "x1"; then
   if test "x$USE_SSLEAY" = "x1" -o "x$USE_WINDOWS_SSPI" = "x1" \