catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I2196fd0d1fad0901ea083371c8d2d07dfbe4ef78
diff --git a/src/sel_logger.cpp b/src/sel_logger.cpp
index 5aa28ae..b7f6a77 100644
--- a/src/sel_logger.cpp
+++ b/src/sel_logger.cpp
@@ -148,7 +148,7 @@
     {
         sdbusplus::message::message reloadResponse = dbus->call(rsyslogReload);
     }
-    catch (sdbusplus::exception_t& e)
+    catch (const sdbusplus::exception_t& e)
     {
         std::cerr << e.what() << "\n";
     }