vcxproj: avoid escaping double quotes in the defines

Visual Studio 2022 does not like that at all.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

contrib/buildsystems/Generators/Vcxproj.pm

@@ -88,6 +88,7 @@ sub createProject {
     $defines =~ s/</&lt;/g;
     $defines =~ s/>/&gt;/g;
     $defines =~ s/\'//g;
+    $defines =~ s/\\"/"/g;
 
     my $rcdefines = $defines;
     $rcdefines =~ s/(?<!\\)"/\\$&/g;