minor fixes to waveform plot

This MR fixes a couple of bugs in the waveform plotting.

• for png/pdf format the x-axis range in the time domain was being incorrectly set
• for html format the time domain injection wasn't being plotted

bilby/gw/result.py

@@ -344,7 +344,9 @@ class CompactBinaryCoalescenceResult(CoreResult):
         logger.debug("Downsampling frequency mask to {} values".format(
             len(frequency_idxs))
         )
-        plot_times = interferometer.time_array[time_idxs] - interferometer.strain_data.start_time
+        plot_times = interferometer.time_array[time_idxs]
+        if format == "html":
+            plot_times -= interferometer.strain_data.start_time
         plot_frequencies = interferometer.frequency_array[frequency_idxs]
 
         waveform_generator = WaveformGenerator(
@@ -377,7 +379,7 @@ class CompactBinaryCoalescenceResult(CoreResult):
                 ht_inj_det = infft(
                     hf_inj_det /
                     interferometer.amplitude_spectral_density_array,
-                    self.sampling_frequency)[time_idxs],
+                    self.sampling_frequency)[time_idxs]
                 if format == "html":
                     fig.add_trace(
                         go.Scatter(
@@ -415,10 +417,7 @@ class CompactBinaryCoalescenceResult(CoreResult):
                             1 / interferometer.strain_data.duration),
                         color='k', label='injected', linestyle='--')
                     axs[1].plot(
-                        plot_times,
-                        infft(hf_inj_det /
-                              interferometer.amplitude_spectral_density_array,
-                              self.sampling_frequency)[time_idxs],
+                        plot_times, ht_inj_det,
                         color='k', linestyle='--')
                 logger.debug('Plotted injection.')
             except IndexError: