Errors when setting `labels` parameter

[sjockers]

For certain queries, setting the labels parameter to either both or name causes an error.

Example

Works:

• https://tabular.genesapi.org/?region=all&level=3&parent=08&data=99910%3AAI0201&format=csv&layout=region&time=2017&labels=id
• https://tabular.genesapi.org/?region=all&level=3&parent=08&data=99910%3AAI0201&format=csv&layout=region&time=2017

Does not work:

• https://tabular.genesapi.org/?region=all&level=3&parent=08&data=99910%3AAI0201&format=csv&layout=region&time=2017&labels=both
• https://tabular.genesapi.org/?region=all&level=3&parent=08&data=99910%3AAI0201&format=csv&layout=region&time=2017&labels=name