Get rid of double spaces in UK postcode and PL street name

PL:
````ruby
Faker::Address.street_name => "ul.  Filipek" # two spaces
````
UK:
````ruby
Faker::Address.postcode => "Z5  5JL" # also two spaces
````
ES:
````ruby
Faker::Address.street_address => "Extramuros Benjamín Benavides  1 Puerta 112" # also two spaces
````

Now there is only one space.