myria_web_main.py: remove parens from connection string
myria_web_main.py: remove parens from connection string

Signed-off-by: Daniel Halperin <1a02732a15f637c31107256cbee5819e36aa7c67@cs.washington.edu>

uwescience/myria-web,uwescience/myria-web,uwescience/myria-web,uwescience/myria-web