catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9e474f2b3e936b9961eaa08693744c466736e768
diff --git a/src/ADCSensor.cpp b/src/ADCSensor.cpp
index 8c335e5..e367c17 100644
--- a/src/ADCSensor.cpp
+++ b/src/ADCSensor.cpp
@@ -172,7 +172,7 @@
             nvalue = std::round(nvalue * roundFactor) / roundFactor;
             updateValue(nvalue);
         }
-        catch (std::invalid_argument&)
+        catch (const std::invalid_argument&)
         {
             incrementError();
         }