configure: Fix detection of gnutls on Ubuntu 14.10.

[Sebastian Lackner]

On 18.11.2014 07:52, Nicolas Le Cam wrote:
> 2014-11-17 9:37 GMT+01:00 Sebastian Lackner <sebastian at fds-team.de>:
>> Someone asked me to submit this, although its very Ubuntu specific.
>>
>> On some Ubuntu versions there only exists a package where libgnutls was renamed to libgnutls-deb0. As an effect ./configure fails to detect it properly because it compares the exact soname.
>>
>> http://packages.ubuntu.com/precise/amd64/libgnutls28/filelist
>> http://packages.ubuntu.com/utopic/amd64/libgnutls-deb0-28/filelist
>>
>> ---
>>  configure.ac | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>>
>>
> 
> Hi Sebastian,
> 
> This also fixes libgnutls detection on Debian testing (and futur
> Jessie) and derivatives.
> 
> What about [[libgnutls\\(-deb[[0-9]]\\)\\{0,1\\}]] or
> [[libgnutls\\(-[[0-9A-Za-z]]\+\\)\\{0,1\\}]] instead.
> I don't think the debian specific soname will bump too often but it
> could avoid the need for another patch.
> 

The second idea would also match libgnutls-openssl. Not sure if that hurts, but so far this check only matches 'real' gnutls, and not the openssl wrapper lib.