caddytls: Reuse certificate cache through reloads (#5623)

* caddytls: Don't purge cert cache on config reload

* Update CertMagic

This actually avoids reloading managed certs from storage
when already in the cache, d'oh.

* Fix bug; re-implement HasCertificateForSubject

* Update go.mod: CertMagic tag

1 files changed, 3 insertions, 2 deletions

diff --git a/caddy.go b/caddy.go
index 84cfc11cf..dcaa86b04 100644
--- a/caddy.go
+++ b/caddy.go
@@ -959,8 +959,9 @@ func Version() (simple, full string) {
 // This function is experimental and might be changed
 // or removed in the future.
 func ActiveContext() Context {
-	currentCtxMu.RLock()
-	defer currentCtxMu.RUnlock()
+	// TODO: This locking might still be needed; more investigation is required (deadlock during Cleanup for the caddytls.TLS module).
+	// currentCtxMu.RLock()
+	// defer currentCtxMu.RUnlock()
 	return currentCtx
 }