BaseFilter.loadProperties() silently skips null/empty filter file entries

[elharo]

In src/main/java/org/apache/maven/shared/filtering/BaseFilter.java, line 192:

if (filterFile == null || filterFile.trim().isEmpty()) {
    // skip empty file name
    continue;
}

Null or empty entries in the filters list are silently skipped. If a caller accidentally includes an empty string in their filter list (e.g., from a malformed POM), no warning or error is logged. The problem is silently masked.