Fix spelling error

dovecot/lang/en

@@ -61,9 +61,9 @@ ssl_hours=hours
 ssl_none=None
 ssl_plain=Disallow plaintext authentication in non-SSL mode?
 ssl_err=Failed to save SSL configuration
-ssl_ekey=Missing or non-existant private key file
-ssl_ecert=Missing or non-existant certificate file
-ssl_eca=Missing or non-existant CA certificate file
+ssl_ekey=Missing or non-existent private key file
+ssl_ecert=Missing or non-existent certificate file
+ssl_eca=Missing or non-existent CA certificate file
 ssl_eregen=Missing or non-numeric parameter regeneration interval
 ssl_epass=No SSL key file password entered
 
@@ -108,13 +108,13 @@ login_pam=PAM service $1
 login_session=Open and close PAM sessions
 login_pam2=PAM service $1<br>&nbsp;&nbsp;$2<br>&nbsp;&nbsp;Use cache key $3
 login_other=Other Dovecot setting $1
-login_epasswdfile=Missing or non-existant custom password file
+login_epasswdfile=Missing or non-existent custom password file
 login_euid=Missing or non-numeric UID
 login_egid=Missing or non-numeric GID
 login_ehome=Missing home directory
-login_eldap=Missing or non-existant LDAP configuration file
-login_epgsql=Missing or non-existant PostgreSQL configuration file
-login_esql=Missing or non-existant SQL configuration file
+login_eldap=Missing or non-existent LDAP configuration file
+login_epgsql=Missing or non-existent PostgreSQL configuration file
+login_esql=Missing or non-existent SQL configuration file
 login_eppam=Missing or invalid PAM service
 login_bsdauth=BSD authentication<br>&nbsp;&nbsp;Use cache key $1
 login_checkpassword=External program $1