use EAFP instead of LBYL

src/cal_tools/gotthard2/gotthard2lib.py

@@ -26,10 +26,10 @@ class Gotthard2Ctrl():
             self.run_dc[self.ctrl_src, "exposurePeriod"].as_single_value(), 4))  # noqa
 
     def get_acquisition_rate(self):
-        if "acquisitionRate.value" in self.run_dc.get_run_values(self.ctrl_src):  # noqa
-            return(
-                float(self.run_dc.get_run_value(
-                    self.ctrl_src, "acquisitionRate")))
+        try:
+            return(float(self.run_dc.get_run_value(self.ctrl_src, "acquisitionRate")))  # noqa
+        except extra_data.PropertyNameError:
+            pass
 
     def get_single_photon(self):
         if "singlePhoton.value" in self.run_dc.keys_for_source(self.ctrl_src):  # noqa