Re-enable .cpp as LF in .gitattributes

.gitattributes

 
 # Files with Unix line endings
 *.c   text eol=lf
-# *.cpp text eol=lf
+*.cpp text eol=lf
 *.h   text eol=lf
 *.ino text eol=lf
 *.py  text eol=lf