Photo_licensed=false URL string returns observations with only sound recordings

[pisum]

@jdmore

Single license queries are already available from the Filters panels. To query for multiple license types:

• &photo_licensed=cc0,cc-by,cc-by-sa (example for all photo licenses accepted by Wikipedia)
• &photo_licensed=cc0,cc-by,cc-by-nc (example for all photo licenses accepted by GBIF)
• &sound_licensed=cc0,cc-by (example for multiple sound licenses

i corrected these in the wiki thread since they were wrong.