catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: If18cc0293b52ce5f7f8e068688aa17d28ed27d50
diff --git a/command/payload_cmds.cpp b/command/payload_cmds.cpp
index 1413e6c..01e1117 100644
--- a/command/payload_cmds.cpp
+++ b/command/payload_cmds.cpp
@@ -92,7 +92,7 @@
         sol::Manager::get().startPayloadInstance(request->payloadInstance,
                                                  handler->sessionID);
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         log<level::ERR>(e.what());
         response->completionCode = IPMI_CC_UNSPECIFIED_ERROR;
@@ -159,7 +159,7 @@
         {
             activating(request->payloadInstance, sessionID);
         }
-        catch (std::exception& e)
+        catch (const std::exception& e)
         {
             log<level::INFO>(e.what());
             /*
@@ -171,7 +171,7 @@
             return outPayload;
         }
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         log<level::ERR>(e.what());
         response->completionCode = IPMI_CC_UNSPECIFIED_ERROR;