Modify cmake/packaging/distrib/osx/welcome.txt to not have two spaces.
Modify cmake/packaging/distrib/osx/welcome.txt to not have two spaces.

nickerso/libcellml,hsorby/libcellml,hsorby/libcellml,cellml/libcellml,hsorby/libcellml,cellml/libcellml,nickerso/libcellml,MichaelClerx/libcellml,nickerso/libcellml,hsorby/libcellml,MichaelClerx/libcellml,cellml/libcellml,nickerso/libcellml,MichaelClerx/libcellml,cellml/libcellml