package/libfreeimage: fix build with gcc 11

package/libfreeimage: fix build with gcc 11

Fix the following build failure with gcc 11:

In file included from Source/FreeImage/../OpenEXR/IlmImf/ImfHeader.h:51,
                 from Source/FreeImage/../OpenEXR/IlmImf/ImfOutputFile.h:46,
                 from Source/FreeImage/PluginEXR.cpp:33:
Source/OpenEXR/Imath/ImathVec.h:228:41: error: ISO C++17 does not allow dynamic exception specifications
  228 |     const Vec2 &        normalizeExc () throw (IEX_NAMESPACE::MathExc);
      |                                         ^~~~~

Fixes:
 - http://autobuild.buildroot.org/results/953cd07402fe2f99f2361a3b4a7b086a88e0d72d

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>