deps: escape Python strings correctly

Fixes: #50671
PR-URL: #50695
Reviewed-By: Christian Clauss <cclauss@me.com>
Reviewed-By: Jithil P Ponnan <jithil@outlook.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

deps/openssl/openssl_common.gypi

@@ -26,7 +26,7 @@
     }, 'OS=="win"', {
       'defines': [
         ## default of Win. See INSTALL in openssl repo.
-        'OPENSSLDIR="C:\\\Program\ Files\\\Common\ Files\\\SSL"',
+        'OPENSSLDIR="C:\\\\Program\\ Files\\\\Common\\ Files\\\\SSL"',
         'ENGINESDIR="NUL"',
         'OPENSSL_SYS_WIN32', 'WIN32_LEAN_AND_MEAN', 'L_ENDIAN',
         '_CRT_SECURE_NO_DEPRECATE', 'UNICODE', '_UNICODE',