GRASS_INT_ZLIB only applies to CELL type

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@49684 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/init/variables.html

@@ -170,8 +170,8 @@ PERMANENT
 
   <dt>GRASS_INT_ZLIB</dt>
   <dd>[libgis]<br> if the environment variable GRASS_INT_ZLIB exists,
-    new compressed rasters will be compressed using zlib instead of
-    RLE compression. Such rasters will have a <tt>compressed</tt>
+    new compressed <i>integer</i> (CELL type) raster maps will be compressed
+    using zlib instead of RLE compression. Such rasters will have a <tt>compressed</tt>
     value of 2 in the cellhd file.
     <br><br>
     Obviously, decompression is controlled by the