Catch the right exception for config errors

This originally belonged to #15.

src/scdaq.cc

@@ -205,10 +205,10 @@ if(argc < 2){
 
     //    utility::report_elapsed_time((tbb::tick_count::now() - mainStartTime).seconds());
     return retval;
-  } catch (std::exception& e) {
+  } catch (std::invalid_argument& e) {
     LOG(FATAL) << "Configuration invalid! Error text is \"" << e.what() << "\" Bailing out.";
     return EX_CONFIG;
-  } catch(std::exception& e) {
+  } catch (std::exception& e) {
     LOG(ERROR) << "Error occurred. error text is: \"" << e.what() << "\"";
     return 1;
   }