Merge pull request #187 from jburgess777/icebox-compile-warning

Fix compile warning in icetime.cc

icetime/icetime.cc

diff --git a/icetime/icetime.cc b/icetime/icetime.cc
index 35ce99a..c49e2e2 100644
--- a/icetime/icetime.cc
+++ b/icetime/icetime.cc
@@ -1320,7 +1320,7 @@
 		} else {
 			return ec_name;
 		}
-	} catch(std::invalid_argument e) { // Not numeric and stoi throws exception
+	} catch(std::invalid_argument &e) { // Not numeric and stoi throws exception
 		return ec_name;
 	}