test: fix flaky qsync_with_anon.test.lua

The test used very small timeout, 0.1 second, to test that a sync
transaction works fine. But with too much load on the machine this
may appear not enough. Now in the cases where the timeout wasn't
supposed to explode the value 1000 seconds is used, more than
enough.

Closes #5165

test/replication/qsync_with_anon.result

@@ -48,7 +48,7 @@ test_run:switch('default')
  | ---
  | - true
  | ...
-box.cfg{replication_synchro_quorum=NUM_INSTANCES, replication_synchro_timeout=0.1}
+box.cfg{replication_synchro_quorum=NUM_INSTANCES, replication_synchro_timeout=1000}
  | ---
  | ...
 _ = box.schema.space.create('sync', {is_sync=true, engine=engine})
@@ -126,7 +126,7 @@ test_run:switch('default')
  | ---
  | - true
  | ...
-box.cfg{replication_synchro_quorum=NUM_INSTANCES}
+box.cfg{replication_synchro_quorum=NUM_INSTANCES, replication_synchro_timeout=1000}
  | ---
  | ...
 box.space.sync:insert{1} -- success

test/replication/qsync_with_anon.test.lua

@@ -19,7 +19,7 @@ test_run:cmd('switch replica_anon')
 -- replica.
 -- Testcase setup.
 test_run:switch('default')
-box.cfg{replication_synchro_quorum=NUM_INSTANCES, replication_synchro_timeout=0.1}
+box.cfg{replication_synchro_quorum=NUM_INSTANCES, replication_synchro_timeout=1000}
 _ = box.schema.space.create('sync', {is_sync=true, engine=engine})
 _ = box.space.sync:create_index('pk')
 -- Testcase body.
@@ -45,7 +45,7 @@ box.space.sync:insert{1} -- failure
 test_run:cmd('switch replica_anon')
 box.space.sync:select{} -- none
 test_run:switch('default')
-box.cfg{replication_synchro_quorum=NUM_INSTANCES}
+box.cfg{replication_synchro_quorum=NUM_INSTANCES, replication_synchro_timeout=1000}
 box.space.sync:insert{1} -- success
 test_run:cmd('switch replica_anon')
 box.space.sync:select{} -- 1