fix(email): IMAP Security dropdown matches outgoing — no port in label, manual port

Reverts the auto-fill; drops the (993)/(143) from the Security option labels so
incoming behaves exactly like the outgoing SMTP card (plain SSL/TLS vs
STARTTLS, port set manually).

frontend/src/i18n/locales/de.json

@@ -2481,8 +2481,8 @@
       "host": "IMAP-Host",
       "port": "Port",
       "security": "Sicherheit",
-      "ssl": "SSL/TLS (993)",
-      "plain": "Keine / STARTTLS (143)",
+      "ssl": "SSL/TLS",
+      "plain": "Keine / STARTTLS",
       "user": "Benutzername",
       "pass": "Passwort",
       "folder": "Ordner",

frontend/src/i18n/locales/en.json

@@ -2054,8 +2054,8 @@
       "host": "IMAP host",
       "port": "Port",
       "security": "Security",
-      "ssl": "SSL/TLS (993)",
-      "plain": "None / STARTTLS (143)",
+      "ssl": "SSL/TLS",
+      "plain": "None / STARTTLS",
       "user": "Username",
       "pass": "Password",
       "folder": "Folder",