MINOR: ssl: ignore dotfiles when loading a dir w/ ca-file

Ignore the files starting with a dot when trying to load a directory
with the "ca-file directive".
diff --git a/doc/configuration.txt b/doc/configuration.txt
index b9e6e80..f4aba09 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -13764,7 +13764,7 @@
   designates a PEM file from which to load CA certificates used to verify
   client's certificate. It is possible to load a directory containing multiple
   CAs, in this case HAProxy will try to load every ".pem", ".crt", ".cer", and
-  .crl" available in the directory.
+  .crl" available in the directory, files starting with a dot are ignored.
 
 ca-ignore-err [all|<errorID>,...]
   This setting is only available when support for OpenSSL was built in.
@@ -14552,7 +14552,7 @@
   designates a PEM file from which to load CA certificates used to verify
   server's certificate. It is possible to load a directory containing multiple
   CAs, in this case HAProxy will try to load every ".pem", ".crt", ".cer", and
-  .crl" available in the directory.
+  .crl" available in the directory, files starting with a dot are ignored.
 
   In order to use the trusted CAs of your system, the "@system-ca" parameter
   could be used in place of the cafile. The location of this directory could be