Formspec: Fix newline conversion on Windows (#16311)

Strings with CR+LF (\r+\n) were wrongly fixed into \r, which is enough to display them correctly, but the missing \n became important once the text was saved/reloaded.

By removing the \r instead of the \n, then the text is displayed correctly and saved correctly.

irr/src/CGUIEditBox.cpp

@@ -1104,10 +1104,7 @@ void CGUIEditBox::breakText()
 			lineBreak = true;
 			c = 0;
 			if (Text[i + 1] == L'\n') { // Windows breaks
-				// TODO: I (Michael) think that we shouldn't change the text given by the user for whatever reason.
-				// Instead rework the cursor positioning to be able to handle this (but not in stable release
-				// branch as users might already expect this behavior).
-				Text.erase(i + 1);
+				Text.erase(i);
 				--size;
 				if (CursorPos > i)
 					--CursorPos;