[LyX/master] Correct the description of Lexer::getLongString

[Jean-Marc Lasgouttes]

commit 8ec3397da32ff9af970b98d4de2440a86d846bd3
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Tue Jan 10 16:25:48 2023 +0100

    Correct the description of Lexer::getLongString
    
    The fact that it does not work with tabs has been fixed long ago.
---
 src/Lexer.h |   10 ++++------
 1 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/Lexer.h b/src/Lexer.h
index 6ecdd90..02ec747 100644
--- a/src/Lexer.h
+++ b/src/Lexer.h
@@ -138,12 +138,10 @@ public:
 	std::string const getString(bool trim = false) const;
 	///
 	docstring const getDocString(bool trim = false) const;
-	/** Get a long string, ended by the tag `endtoken'.
-	    This string can span several lines. The first line
-	    serves as a template for how many spaces the lines
-	    are indented. This much white space is skipped from
-	    each following line. This mechanism does not work
-	    perfectly if you use tabs.
+	/** Get a long string, ended by the tag `endtoken'. This string
+	    can span several lines. The first line serves as a template
+	    for what sequence of tabs and spaces make up the indentation.
+	    This prefix is skipped from each following line.
 	*/
 	docstring getLongString(docstring const & endtoken);