fix: correct subject format for certificate generation on Windows

Author: bjohansebas

test/support/gencert.sh

@@ -10,7 +10,7 @@ CERT_PATH="./test/fixtures/server.crt"
 SUBJ="/C=US/ST=Illinois/L=Chicago/O=node-express-session/CN=express-session.local"
 
 if [[ "$OS" == MINGW* || "$OS" == MSYS* ]]; then
-  SUBJ="\/C=US/ST=Illinois/L=Chicago/O=node-express-session/CN=express-session.local"
+  SUBJ=/"/C=US/ST=Illinois/L=Chicago/O=node-express-session/CN=express-session.local"
 fi
 
 openssl req -x509 -nodes -newkey rsa:2048 -keyout ./test/fixtures/server.key -out ./test/fixtures/server.crt -days 3650 \