change deafult thread num (#2590)

Co-authored-by: chejinge <chejinge@360.cn>

conf/pika.conf

@@ -29,7 +29,7 @@ thread-pool-size : 12
 
 # Size of the low level thread pool, The threads within this pool
 # are dedicated to handling slow user requests.
-slow-cmd-thread-pool-size : 4
+slow-cmd-thread-pool-size : 1
 
 # Slow cmd list e.g. hgetall, mset
 slow-cmd-list :
@@ -363,7 +363,7 @@ max-bytes-for-level-multiplier : 10
 slotmigrate : no
 
 # slotmigrate thread num
-slotmigrate-thread-num : 8
+slotmigrate-thread-num : 1
 
 # thread-migrate-keys-num  1/8 of the write_buffer_size_
 thread-migrate-keys-num : 64