add Testsuite-Triggers to tagfile-order

Added in dpkg in commit 90324cfa942ba23d5d44b28b1087fbd510340502.

apt-pkg/tagfile-order.c

@@ -81,6 +81,7 @@ static const char *iTFRewriteSourceOrder[] = {
    "Build-Conflicts-Arch",
    "Build-Conflicts-Indep",
    "Testsuite",
+   "Testsuite-Triggers",
    "Homepage",
    "Vcs-Browser",
    "Vcs-Browse", // dak only (nickname?)