[PATCH for-5.2] meson: Fix argument for makensis (build regression)

[Stefan Weil]

`make installer` with a DLL directory was broken.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
---
 scripts/nsis.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/nsis.py b/scripts/nsis.py
index e1c409344e..5135a05831 100644
--- a/scripts/nsis.py
+++ b/scripts/nsis.py
@@ -65,7 +65,7 @@ def main():
             dlldir = "w64"
             makensis += ["-DW64"]
         if os.path.exists(os.path.join(args.srcdir, "dll")):
-            makensis += "-DDLLDIR={0}/dll/{1}".format(args.srcdir, dlldir)
+            makensis += ["-DDLLDIR={0}/dll/{1}".format(args.srcdir, dlldir)]
 
         makensis += ["-DOUTFILE=" + args.outfile] + args.nsisargs
         subprocess.run(makensis)
-- 
2.29.2