Remove libicu symlinks without any version numbers in 5.0.0-rc1 installers

For Linux installers the ICU libs are prebuilt and bundled into installers.
Symlinks without any version numbers should be removed to avoid possible problems when user tries to rebuild e.g. webkit from sources.

The following files will be bundled into Linux installers:

libicudata.so.49 -> libicudata.so.49.1.2*
libicudata.so.49.1.2*
libicui18n.so.49 -> libicui18n.so.49.1.2*
libicui18n.so.49.1.2*
libicuuc.so.49 -> libicuuc.so.49.1.2*
libicuuc.so.49.1.2*