Fixed Maven exec plugin version
Fixed Maven exec plugin version

AndyGee/microprofile-conference,iainduncani/microprofile-conference,AndyGee/microprofile-conference,microprofile/microprofile-conference,katheris/microprofile-conference,karianna/microprofile-conference,iainduncani/microprofile-conference,karianna/microprofile-conference,katheris/microprofile-conference,katheris/microprofile-conference,microprofile/microprofile-conference,microprofile/microprofile-conference,katheris/microprofile-conference,AndyGee/microprofile-conference,iainduncani/microprofile-conference,karianna/microprofile-conference,AndyGee/microprofile-conference,AndyGee/microprofile-conference,karianna/microprofile-conference,katheris/microprofile-conference,microprofile/microprofile-conference,iainduncani/microprofile-conference,iainduncani/microprofile-conference,microprofile/microprofile-conference,karianna/microprofile-conference