Missed another file for the tarball.

This commit was SVN r24488.

contrib/Makefile.am

@@ -95,6 +95,7 @@ EXTRA_DIST = \
         platform/win32/CMakeModules/find_flex.cmake \
         platform/win32/CMakeModules/find_libltdl.cmake \
         platform/win32/CMakeModules/find_ofed_sdk.cmake \
+        platform/win32/CMakeModules/find_winverbs.cmake \
         platform/win32/CMakeModules/generate_version_file.cmake \
         platform/win32/CMakeModules/get_c_alignment.cmake \
         platform/win32/CMakeModules/list_subdirs.cmake \