catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ice1ca68c7c753bb67a4d8a478399225fc1b0b1f5
diff --git a/serialize.cpp b/serialize.cpp
index c471188..52c5ac5 100644
--- a/serialize.cpp
+++ b/serialize.cpp
@@ -74,7 +74,7 @@
             iarchive(cereal::make_nvp(priorityName, priority));
             return true;
         }
-        catch (cereal::Exception& e)
+        catch (const cereal::Exception& e)
         {
             fs::remove_all(path);
         }
@@ -134,7 +134,7 @@
             iarchive(cereal::make_nvp(purposeName, purpose));
             return true;
         }
-        catch (cereal::Exception& e)
+        catch (const cereal::Exception& e)
         {
             fs::remove_all(path);
         }