Cancel display flags help on Pg error in "migrate"

[alexsuslov]

prestd  migrate up

...
Error: pq: relation "posts" already exists
Usage:
  prestd migrate up [flags]
  prestd migrate up [command]

Available Commands:
  auth        Create auth table

Flags:
  -h, --help   help for up

Global Flags:
      --path string   Migrations directory
      --url string    Database driver url (default "postgres://postgres:postgres@127.0.0.1:5432/prest?sslmode=disable&sslcert=&sslkey=&sslrootcert=")

Use "prestd migrate up [command] --help" for more information about a command.

pq: relation "posts" already exists

It is necessary to disable the display of help on flags on a database error

[arxdsilva]

fixed in #834
released in v1.3.2