Bump src/loggregator

Bump cloudfoundry/loggregator:
  Alex Jackson:
     fix compile error
     bump loggregatorlib to pick up clear method on test logger
     remove mistakenly added listener
     cleanup for deaagent
     [#66514162, #66597944] break on newlines when reading the warden socket instead of reading fixed sized chunks

Signed-off-by: John Tuley <jtuley@pivotallabs.com>