swtpm_localca: Add comment that failure to read optsfile is not an issue

Add a comment stating that failure to read the optsfile is not an
issue since the optsfile does not need to exist.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
diff --git a/src/swtpm_localca/swtpm_localca.c b/src/swtpm_localca/swtpm_localca.c
index 089e4e0..a509fb9 100644
--- a/src/swtpm_localca/swtpm_localca.c
+++ b/src/swtpm_localca/swtpm_localca.c
@@ -370,7 +370,7 @@
     if (get_next_serial(certserial, lockfile, &serial_str) != 0)
         return 1;
 
-    /* try to read the optsfile */
+    /* try to read the optsfile - failure to read is fine */
     read_file_lines(optsfile, &optsfile_lines);
 
     /* split each line from the optsfile and add the stripped parameters to options */