Fixes ZPOPMIN/ZPOPMAX wrong replies when count is 0 with non-zset (#9711)

Moves ZPOP ... 0 fast exit path after type check to reply with
WRONGTYPE. In the past it will return an empty array.

Also now count is not allowed to be negative.

see #9680

before:
```
127.0.0.1:6379> set zset str
OK
127.0.0.1:6379> zpopmin zset 0
(empty array)
127.0.0.1:6379> zpopmin zset -1
(empty array)
```

after:
```
127.0.0.1:6379> set zset str
OK
127.0.0.1:6379> zpopmin zset 0
(error) WRONGTYPE Operation against a key holding the wrong kind of value
127.0.0.1:6379> zpopmin zset -1
(error) ERR value is out of range, must be positive
```

1 files changed, 2 insertions, 2 deletions

diff --git a/src/blocked.c b/src/blocked.c
index 8a2e41463..3723b4fbf 100644
--- a/src/blocked.c
+++ b/src/blocked.c
@@ -363,7 +363,7 @@ void serveClientsBlockedOnSortedSetKey(robj *o, readyList *rl) {
             argv[0] = where == ZSET_MIN ? shared.zpopmin : shared.zpopmax;
             argv[1] = rl->key;
             incrRefCount(rl->key);
-            if (count != 0) {
+            if (count != -1) {
                 /* Replicate it as command with COUNT. */
                 robj *count_obj = createStringObjectFromLongLong((count > llen) ? llen : count);
                 argv[2] = count_obj;
@@ -371,7 +371,7 @@ void serveClientsBlockedOnSortedSetKey(robj *o, readyList *rl) {
             }
             propagate(receiver->db->id, argv, argc, PROPAGATE_AOF|PROPAGATE_REPL);
             decrRefCount(argv[1]);
-            if (count != 0) decrRefCount(argv[2]);
+            if (count != -1) decrRefCount(argv[2]);
 
             /* The zset is empty and has been deleted. */
             if (deleted) break;