[Bug 51951] configure says that libsane development files are not found even though they are present

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=51951

Drew Bugs  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |regression
            Version|6.20                        |unspecified
    Regression SHA1|                            |cf5bad0ecc8976c66ecf73d987b
                   |                            |870d917e625ba