Fix for 8bmb new step scan format

Author: Arthur Glowacki

src/io/file/hl_file_io.h

@@ -1503,6 +1503,14 @@ DLL_EXPORT bool load_spectra_volume(std::string dataset_directory,
                                 }
                             }
                         }
+                    }
+                                        else
+                    {
+                        // copy prev row
+                        if(i>0)
+                        {
+                            (*spectra_volume)[i] = (*spectra_volume)[i-1];
+                        }
                     }
                 }
                 else
@@ -1525,6 +1533,14 @@ DLL_EXPORT bool load_spectra_volume(std::string dataset_directory,
                             }
                         }
                     }
+                    else
+                    {
+                        // copy prev row
+                        if(i>0)
+                        {
+                            (*spectra_volume)[i] = (*spectra_volume)[i-1];
+                        }
+                    }
                 }
             }
         }