--without-gssapi doesn't stop neon from trying to use gssapi and other krb libs

[Travis P]

My workaround:

Building on another system, I don't appear to have problems with the  
gssapi/krb5 libs (they are linked in when neon compiles), but they  
don't cause an error, and so I avoid the problem.

The problem was probably related to my trying to build a 32-bit  
binary for use by various machines (32 and 64-bit) on a 64-bit  
machine which may have only had those gssapi/krb5 libs in 64-bit  
versions.  The build that worked was done on a 32-bit machine.

-Travis