Update elfio

needs c++14, requires move to centOS stream 9 (COSS9) and abandon centos7.

test/SConscript

@@ -34,7 +34,7 @@ LIBS='''
 	ehp
 	'''
 myenv=myenv.Clone(CPPPATH=Split(cpppath))
-myenv.Append(CXXFLAGS = " -std=c++11 -Wall -Werror -fmax-errors=1 -g ")
+myenv.Append(CXXFLAGS = " -std=c++14 -Wall -Werror -fmax-errors=1 -g ")
 
 lib=myenv.Program("test.exe",  Split(files), LIBPATH=Split(LIBPATH), LIBS=Split(LIBS))
 Default(lib)