contrail-stats hangs

[Shreya Kunjir]

Saravanan found out that GetUint() function is used to get u64 data, and that code should have used GetUint64() to get u64 data. Using GetUint() causes overflow and generates corrupt flags_ and negative values in the structure which indirectly results in hanging of contrail-stats command.
These are the two files where error is seen:
shreyak@ubuntu-build02:~/workspace$ vi build/include/rapidjson/document.h
shreyak@ubuntu-build02:~/workspace$ vi controller/src/query_engine/select.cc

[Megh Bhatt (meghb)]

Fixed via https://review.opencontrail.org/#/c/942/