Fix Windows installer build by removing libboost DLLs (#1003)

Msys2 has updated to a version of boost that no longer includes
the libboost-regex-mt and libboost-system-mt DLLs. This change
removes references to these DLLs so that the installer build
stops trying to find them and failing.

tools/jenkins/genDllVersions.sh

@@ -125,9 +125,7 @@ catDll fbclient
 catDll libass-
 catDll libbluray-
 catDll libboost_filesystem-mt
-catDll libboost_regex-mt
 catDll libboost_serialization-mt
-catDll libboost_system-mt
 catDll libboost_thread-mt
 catDll libbz2-
 catDll libcaca-