docker 1.11.x causing high cpu by this plugin

[tehlers320]

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                        
 4463 root      20   0 1199m  23m 9316 S 100.1  0.6   9814:51 collectd                                                                                       
 2782 root      20   0  355m  15m 9324 S  3.0  0.4 277:25.62 docker-containe                                                                                 
 2775 root      20   0 1213m  56m  23m S  2.3  1.4 344:35.23 docker                 

[boris317]

FYI, This issue is related to #25. The fix proposed in the PR seems to fix the problem of getting stuck in that while loop and consuming all of the CPU.