Remove "-oss" as default greenplum version suffix

The default is a non OSS build across CI. Explict CI jobs that do build
OSS can use `--with-extra-version` to append `-oss`.
Authored-by: NKris Macoskey <kmacoskey@pivotal.io>

configure

@@ -20090,10 +20090,6 @@ BLD_ARCH=`echo $BLD_ARCH`
 
 GP_VERSION_LONG=`bash ./getversion`
 
-if test "$with_extra_version" = "" ; then
-  with_extra_version="-oss"
-fi
-
 GP_VERSION_LONG="$GP_VERSION_LONG$with_extra_version"
 
 echo $GP_VERSION_LONG > VERSION

configure.in

@@ -2587,10 +2587,6 @@ AC_SUBST(BLD_ARCH)
 
 GP_VERSION_LONG=`bash ./getversion`
 
-if test "$with_extra_version" = "" ; then
-  with_extra_version="-oss"
-fi
-
 GP_VERSION_LONG="$GP_VERSION_LONG$with_extra_version"
 
 echo $GP_VERSION_LONG > VERSION