fix: [0km] prevent rrdtool from messing data in specific locale settings

French for instance would make ``rrdtool`` use commas instead of points that are
not read correctly by ``gnuplot``.

bin/0km

@@ -1348,6 +1348,8 @@ cmdline.spec::cmd:vps-stats:run() {
     } >&2
 
     export GNUTERM=qt
+    ## rrdtool fetch will use comma for floating point depending on some locals !
+    export LC_ALL=C
     exec {PFD}> >(exec gnuplot 2>/dev/null)
     gnuplot_pid="$!"
     if [ -z "$opt_follow" ]; then