[core] Correct Hue config value use integer instead of math expression

[21/Apr/2018 13:52:28 -0400] thrift_util  ERROR    Thrift saw exception (this may be expected).
Traceback (most recent call last):
  File "/opt/cloudera/parcels/CDH-5.12.2-1.cdh5.12.2.p0.4/lib/hue/desktop/core/src/desktop/lib/thrift_util.py", line 432, in wrapper
    self.transport.open()
  File "/opt/cloudera/parcels/CDH-5.12.2-1.cdh5.12.2.p0.4/lib/hue/desktop/core/src/desktop/lib/thrift_sasl.py", line 61, in open
    self.sasl = self.sasl_client_factory()
  File "/opt/cloudera/parcels/CDH-5.12.2-1.cdh5.12.2.p0.4/lib/hue/desktop/core/src/desktop/lib/thrift_util.py", line 293, in sasl_factory
    saslc.setAttr("maxbufsize", SASL_MAX_BUFFER.get())
  File "/opt/cloudera/parcels/CDH-5.12.2-1.cdh5.12.2.p0.4/lib/hue/desktop/core/src/desktop/lib/conf.py", line 147, in get
    return self.config.get_value(data, present=present, prefix=self.prefix, coerce_type=True)
  File "/opt/cloudera/parcels/CDH-5.12.2-1.cdh5.12.2.p0.4/lib/hue/desktop/core/src/desktop/lib/conf.py", line 263, in get_value
    return self._coerce_type(raw_val, prefix)
  File "/opt/cloudera/parcels/CDH-5.12.2-1.cdh5.12.2.p0.4/lib/hue/desktop/core/src/desktop/lib/conf.py", line 283, in _coerce_type
    return self.type(raw)
ValueError: invalid literal for int() with base 10: '100*1024*1024'