get_scd_mems requires erase matlab function, test only if available

matlab/tests/test_requestnames.m

@@ -43,6 +43,10 @@ switch request
  case 'scd'
   % scd dummy call with error information in gdat, do not do test (done with rtc)
   do_gdat_call = 0;
+ case 'rtc'
+  if exist('erase') ~= 2
+    do_gdat_call = 0; % get_scd_mems works with newer versions which contains erase function
+  end
 end
 
 % logging