Fix description of continuation lines

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@42034 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.mapcalc/r.mapcalc.html

@@ -560,7 +560,7 @@ as the latter will read each input map only once.
 <p>
 For formulas that the user enters from standard input
 (rather than from the command line), a line continuation feature now exists.
-If the user adds \e to the end of an input line, <em>r.mapcalc</em> assumes that
+If the user adds a backslash to the end of an input line, <em>r.mapcalc</em> assumes that
 the formula being entered by the user continues on to the next input line.
 There is no limit to the possible number of input lines
 or to the length of a formula.