catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ice1ca68c7c753bb67a4d8a478399225fc1b0b1f5
diff --git a/sync_manager_main.cpp b/sync_manager_main.cpp
index 271e67b..db269a9 100644
--- a/sync_manager_main.cpp
+++ b/sync_manager_main.cpp
@@ -31,7 +31,7 @@
         bus.attach_event(loop, SD_EVENT_PRIORITY_NORMAL);
         sd_event_loop(loop);
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         lg2::error("Error in event loop: {ERROR}", "ERROR", e);
         sd_event_unref(loop);