Use Utils::SkipEmptyParts instead of the deprecated one in QString

- Qt 5.14 introduced Qt::Keep/SkipEmptyParts and deprecated these in
QString namespace.
- Qt Creator defined Utils::SkipEmptyParts conditional on the Qt version,
so we use that for flexibility.
- Remove any explicit references to QString::KeepEmptyParts, as it's a
default value.

Change-Id: I72c65e4901ebc4c5422d4835e63fe23fb6ef28ff
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

plugins/fossil/fossilcommitwidget.cpp

@@ -32,6 +32,7 @@
 
 #include <utils/completingtextedit.h>
 #include <utils/qtcassert.h>
+#include <utils/stringutils.h>
 
 #include <QSyntaxHighlighter>
 #include <QTextEdit>
@@ -122,7 +123,7 @@ QStringList FossilCommitWidget::tags() const
         return QStringList();
 
     tagsText.replace(',', ' ');
-    const QStringList tags = tagsText.split(' ', QString::SkipEmptyParts);
+    const QStringList tags = tagsText.split(' ', Utils::SkipEmptyParts);
     return tags;
 }