Better content-type for icons: Firefox@Windows has problems with image/*

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@421 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/webfrontend/pgm2/01_FHEMWEB.pm

@@ -240,7 +240,8 @@ FW_AnswerCall($)
     binmode (FH); # necessary for Windows
     pO join("", <FH>);
     close(FH);
-    $__RETTYPE = "image/*";
+    my @f_ext = split(/\./,$1); #kpb
+    $__RETTYPE = "image/$f_ext[-1]";
     return 1;
   } elsif($arg !~ m/^$__ME(.*)/) {
     Log(5, "Unknown document $arg requested");