Fix typo in user manual

Author: hlinnaka

doc/src/sgml/libpq.sgml

@@ -7158,7 +7158,7 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
     For backwards compatibility with earlier versions of PostgreSQL, if a
     root CA file exists, the behavior of
     <literal>sslmode</literal>=<literal>require</literal> will be the same
-    as that of <literal>verify-ca</literal>, meaning the sever certificate
+    as that of <literal>verify-ca</literal>, meaning the server certificate
     is validated against the CA. Relying on this behavior is discouraged,
     and applications that need certificate validation should always use
     <literal>verify-ca</literal> or <literal>verify-full</literal>.