Crash when using custom highlight definition with indentation-based folding enabled

Creator crashes when opening a file which:

• loads Kate's definition file
• has indentation-based folding enabled
• has at least one line starting with whitespace.

The crash is a result of null pointer reference in Highlighter::applyIndentationBasedFolding(const QString &text) const

m_tabSettings is null, and never set for files other than C++.

To reproduce:
1. Run Creator on Linux (or possibly other environment when default Kate definitions are available)
2. Open a file which will load Kate definition with indentation-based folding, ie *.ccss or haskell
3. Immediate sigsegv

Simple patch working around the issue (but not fixing it properly, ie not setting valid tab settings) attached.