minor #38648 fix APCu installation for the nightly build job (xabbuh)

This PR was merged into the 4.4 branch.

Discussion
----------

fix APCu installation for the nightly build job

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       |
| License       | MIT
| Doc PR        |

Commits
-------

53434c2bec fix APCu installation for the nightly build job

.travis.yml

@@ -157,15 +157,14 @@ before_install:
           fi
           if [[ $PHP = nightly ]]; then
               tfold ext.memcached tpecl memcached-3.1.5 memcached.so $INI
-              tfold ext.apcu install_apcu_dev 9c36db45100d4d27ec33072f4be90f1f5a0108b7 $INI
           else
-              tfold ext.apcu tpecl apcu-5.1.19 apcu.so $INI
               tfold ext.mongodb tpecl mongodb-1.6.16 mongodb.so $INI
               tfold ext.zookeeper tpecl zookeeper-0.7.2 zookeeper.so $INI
               tfold ext.amqp tpecl amqp-1.10.2 amqp.so $INI
               tfold ext.redis tpecl redis-5.2.2 redis.so $INI "no"
           fi
 
+          tfold ext.apcu tpecl apcu-5.1.19 apcu.so $INI
           tfold ext.igbinary tpecl igbinary-3.1.6 igbinary.so $INI
       done
     - |