catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Id1b5054d3147c39d98309bc11ed7016d6909e2a6
diff --git a/json_config.hpp b/json_config.hpp
index 6322e6e..60e535d 100644
--- a/json_config.hpp
+++ b/json_config.hpp
@@ -283,7 +283,7 @@
                 // Enable ignoring `//` or `/* */` comments
                 jsonConf = json::parse(file, nullptr, true, true);
             }
-            catch (std::exception& e)
+            catch (const std::exception& e)
             {
                 log<level::ERR>(
                     fmt::format(