os400qc3: enable passphrase-protected PEM file support using pem.c
diff --git a/src/os400qc3.c b/src/os400qc3.c
index 0bdf538..aacac4a 100644
--- a/src/os400qc3.c
+++ b/src/os400qc3.c
@@ -2005,7 +2005,7 @@
     fseek(fp, 0L, SEEK_SET);
     for (;;) {
         ret = _libssh2_pem_parse(session, header, trailer,
-                                 NULL,
+                                 passphrase,
                                  fp, &data, &datalen);
 
         if (!ret) {