Backport update_popcon fix

debian/changelog

@@ -21,6 +21,8 @@ debian-cd (3.1.21-stretch) UNRELEASED; urgency=medium
         jigdo files, to reduce load on the service.
     + Fix up ordering in imagesums
     + Add a "with firmware" text to the DISKINFO string when appropriate
+    + tools/update_popcon: cope with lower-case HTTP headers too; Debian
+      just enabled http2 so this broke
 
  -- Steve McIntyre <93sam@debian.org>  Mon, 19 Jun 2017 13:39:58 +0100
 

tools/update_popcon

@@ -36,7 +36,7 @@ dl_file () {
     # We've had problems in the past with download failures causing issues,
     # so let's make sure that we get the complete file in each case
     DIST=$1
-    SITE="http://popcon.debian.org/"
+    SITE="https://popcon.debian.org/"
 
     curl -L $capath -s --head $SITE/$DIST/by_inst > $TDIR/$DIST.head
     error=$?
@@ -45,7 +45,7 @@ dl_file () {
         exit 1
     fi
     HEAD_SIZE=`cat $TDIR/$DIST.head | \
-               awk '/^Content-Length/ {gsub("\r","");print $2}'`
+               awk '/^.ontent-.ength/ {gsub("\r","");print $2}'`
 
     curl -L $capath -s $SITE/$DIST/by_inst > $TDIR/$DIST
     error=$?
@@ -55,14 +55,14 @@ dl_file () {
         exit 1
     fi
 
-    if [ $DL_SIZE != $HEAD_SIZE ] ; then
+    if [ "$DL_SIZE"x != "$HEAD_SIZE"x ] ; then
         echo "Failed to download correctly: expected $HEAD_SIZE bytes, but got $DL_SIZE bytes" >&2
         exit 1
     fi
 
-    LASTMOD=`awk '/^Last-Modified:/ {
+    LASTMOD=`awk '/^.ast-.odified:/ {
                  gsub("\r","")
-                 gsub("^Last-Modified: ","")
+                 gsub("^.ast-.odified: ","")
                  print $0}' $TDIR/$DIST.head`
     echo "$LASTMOD"
 }