Silence gcc 8 warning wrt catch by value

Change-Id: Ice29df6b695b2deba7ddf43be2e711614ab3cdea
Signed-off-by: Matthew Bentham <matthew.bentham@arm.com>
diff --git a/src/armnnQuantizer/QuantizationDataSet.cpp b/src/armnnQuantizer/QuantizationDataSet.cpp
index ac819dc..007cf0a 100644
--- a/src/armnnQuantizer/QuantizationDataSet.cpp
+++ b/src/armnnQuantizer/QuantizationDataSet.cpp
@@ -75,7 +75,7 @@
     {
         passId = static_cast<unsigned int>(std::stoi(csvRows[rowIndex].values[0]));
     }
-    catch (std::invalid_argument)
+    catch (const std::invalid_argument&)
     {
         throw armnn::ParseException("Pass ID [" + csvRows[rowIndex].values[0] + "]" +
                                     " is not correct format on CSV row " + std::to_string(rowIndex));
@@ -90,7 +90,7 @@
     {
         bindingId = std::stoi(csvRows[rowIndex].values[1]);
     }
-    catch (std::invalid_argument)
+    catch (const std::invalid_argument&)
     {
         throw armnn::ParseException("Binding ID [" + csvRows[rowIndex].values[0] + "]" +
                                     " is not correct format on CSV row " + std::to_string(rowIndex));