Change error score formula

[wicochandra]

Change score formula to {<number of unique url errror in issues}/{number of url in job inspections}

E.g.
job inspection:

scope	url
1	A
1	B
1	C
2	A
2	D

Issues:

scope	url	message	type
1	A	error 1	error
1	A	error 2	error
1	B	error 1	error
2	A	error 3	error
2	D	warning 1	warning

Calculation:

{number of unique url in issues} = 3

• scope 1 - A and B
• scope 2 - A

{number of url in job inspections} = 5
Score = 3/5 = 0.6