vnc/spice: fix "never" and "now" expire_time
diff --git a/monitor.c b/monitor.c
index 4c92d38..6aa1bb9 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1136,9 +1136,9 @@
     time_t when;
     int rc;
 
-    if (strcmp(whenstr, "now")) {
+    if (strcmp(whenstr, "now") == 0) {
         when = 0;
-    } else if (strcmp(whenstr, "never")) {
+    } else if (strcmp(whenstr, "never") == 0) {
         when = TIME_MAX;
     } else if (whenstr[0] == '+') {
         when = time(NULL) + strtoull(whenstr+1, NULL, 10);