Allow MYSHELL to be missing from .autocgalrc since when unsued testers just set it to ""

Scripts/developer_scripts/autotest_cgal_with_cmake

@@ -48,7 +48,7 @@ FTP_OPTS="-p -v -n"
 UPLOAD_RESULT_DESTINATION="cgaltest@cgal.geometryfactory.com:incoming"
 BUILD_HOSTS="must_be_set_in_.autocgalrc"
 MAIL_ADDRESS="must_be_set_in_.autocgalrc"
-MYSHELL="must_be_set_in_.autocgalrc"
+MYSHELL=""
 REFERENCE_PLATFORMS_DIR="must_be_set_in_.autocgalrc"
 ACTUAL_DIR=`pwd`
 FTP="ftp"
@@ -669,10 +669,6 @@ ACTUAL_LOGFILE="${CGAL_ROOT}/`basename ${0}`.log"
 rm -f "${ACTUAL_LOGFILE}"
 
 # Sanity checks
-if [ "${MYSHELL}" = "must_be_set_in_.autocgalrc" ]; then
-  error "MYSHELL must be set in .autocgalrc"
-fi
-
 if [ "${REFERENCE_PLATFORMS_DIR}" = "must_be_set_in_.autocgalrc" ]; then
   error "REFERENCE_PLATFORMS_DIR must be set in .autocaglrc"
 fi