UBW importer incorrectly targets a fixed sheet number

[tinne]

In order to correctly import UBW work records, the importer needs to target a sheet with a fixed name (“Aufwände gesamt”) instead of targeting sheet number 2 ignorant of any edits that may have happened to the sheet template in its generation.

Here is a patch to get the idea (untested and obviously not production-ready):

Index: budgeteer-ubw-importer/src/main/java/org/wickedsource/budgeteer/importer/ubw/UBWWorkRecordsImporter.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- budgeteer-ubw-importer/src/main/java/org/wickedsource/budgeteer/importer/ubw/UBWWorkRecordsImporter.java	(revision a1a9033cd3e3905ed3b1c20d58d6f8b7e87225b4)
+++ budgeteer-ubw-importer/src/main/java/org/wickedsource/budgeteer/importer/ubw/UBWWorkRecordsImporter.java	(date 1572944003776)
@@ -40,7 +40,7 @@
             if (!checkValidity(workbook)) {
                 throw new InvalidFileFormatException("Invalid file", file.getFilename());
             }
-            Sheet sheet = workbook.getSheetAt(SHEET_INDEX);
+            Sheet sheet = workbook.getSheet("Aufwände gesamt");
             int i = 3;
             Row row = sheet.getRow(i);
             while (row != null && row.getCell(0) != null && row.getCell(0).getStringCellValue() != null) {