rasql fails if http_proxy env var is set

[Dimitar Misev]

If http_proxy env variable is set in bash, then running a query using the rasql client from the terminal will direct the query to the proxy and the query will fail:

$ echo $http_proxy
http://...
$ rasql -q 'select version()'
rasql: rasdaman query tool v1.0, rasdaman 9.5.0.
opening database RASBASE at localhost:7001...[ERROR] - The client failed to connect to rasserver.
rasdaman error 0: The client failed to contact the server.
rasql done.

Disabling the proxy for the user running the query makes it work again:

$ unset http_proxy
$ rasql -q 'select version()'
rasql: rasdaman query tool v1.0, rasdaman 9.5.0.
opening database RASBASE at localhost:7001...ok
Executing retrieval query...ok
rasql done.

The newer version of grpc — to which we upgraded since 9.5 — suddenly respects this http_proxy environment variable so this is the source of the problem: ​https://github.com/grpc/grpc/blob/master/doc/environment_variables.md

To fix it I'd suggest to unset the http_proxy within rasql.