lamp: install pycurl explicitly with ${pycurl:egg}

Otherwise it will be installed without our special part, using system
curl.
Status Job ID Name Coverage
  External
failed SLAPOS-SR-TEST-MASTER-JEROME

failed SLAPOS-SR-TEST-MASTER-JEROME

05:30:22

canceled SLAPOS-SR-TEST-MASTER-JEROME

00:01:43

canceled SLAPOS-SR-TEST-MASTER-JEROME

00:05:44

running SLAPOS-SR-TEST-MASTER-JEROME

44824:12:44