Use find_package(GIFLIB)

I am not sure if it is correct but otherwise find_package(GIF) picks up
system framework not the generate `giflib*` cmake files

Author: theirix

recipes/leptonica/all/conanfile.py

@@ -130,6 +130,7 @@ def _patch_sources(self):
             replace_in_file(self, cmakelists_src, "if (ZLIB_LIBRARIES)", "if(0)")
             replace_in_file(self, cmake_configure, "if (ZLIB_FOUND)", "if(0)")
         ## giflib
+        replace_in_file(self, cmakelists, "find_package(GIF)", "find_package(GIFLIB)")
         replace_in_file(self, cmakelists_src, "${GIF_LIBRARIES}", "GIF::GIF")
         if not self.options.with_gif:
             replace_in_file(self, cmakelists_src, "if (GIF_LIBRARIES)", "if(0)")