exception: switch to public sdbus exception

SdBusError was intended to be a private error type inside sdbusplus.
Switch all catch locations to use the general sdbusplus::exception type.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia432ec5539a6af3c761dfbb86916464de5455149
diff --git a/sdbusplus.hpp b/sdbusplus.hpp
index 94db9dd..6787f49 100644
--- a/sdbusplus.hpp
+++ b/sdbusplus.hpp
@@ -137,7 +137,7 @@
             }
             return respMsg;
         }
-        catch (const sdbusplus::exception::SdBusError&)
+        catch (const sdbusplus::exception::exception&)
         {
             throw DBusMethodError{busName, path, interface, method};
         }