grant role to user: handle admin roles with space

[pilou-]

Fix Unable to add user when granted role contains a space:

$ awx-cli send <<EOF
[
  {
    "asset_type": "organization",
    "name": "MyOrg",
    "asset_relation": {
      "roles": [
        {
          "name": "Inventory Admin",
          "user": ["misc"],
          "team": []
        }
      ]
    }
  }
]
EOF

ORGANIZATION [MyOrg] ***
Asset up to date
Unable to add user misc to Inventory Admin role: The requested object could not be found.

[coveralls]

Coverage remained the same at 64.318% when pulling 059c195 on pilou-:handle_admin_roles_with_space into a2b151f on ansible:master.

[coveralls]

Coverage remained the same at 64.318% when pulling 059c195 on pilou-:handle_admin_roles_with_space into a2b151f on ansible:master.

[AlanCoding]

thanks, I suspect this code predates those role names, so this is a logical fix