fix dll name in windows setup script

lazpaint/release/windows/lazpaint.iss

@@ -98,7 +98,7 @@ Source: "{#ReleaseDir}lazpaint_x64.exe"; DestDir: "{app}"; DestName: "{#MyAppExe
 Source: "dcraw\dcraw32.exe"; DestDir: "{app}"; DestName: "{#DCRawExeName}"; Flags: ignoreversion; Check: not Is64BitInstallMode
 Source: "dcraw\dcraw_x64.exe"; DestDir: "{app}"; DestName: "{#DCRawExeName}"; Flags: ignoreversion; Check: Is64BitInstallMode
 Source: "libwebp\libwebp32.dll"; DestDir: "{app}"; DestName: "{#LibWebPDllName}"; Flags: ignoreversion; Check: not Is64BitInstallMode
-Source: "libwebp\libwebp64.exe"; DestDir: "{app}"; DestName: "{#LibWebPDllName}"; Flags: ignoreversion; Check: Is64BitInstallMode
+Source: "libwebp\libwebp64.dll"; DestDir: "{app}"; DestName: "{#LibWebPDllName}"; Flags: ignoreversion; Check: Is64BitInstallMode
 Source: "{#ReleaseDir}i18n\*.po"; DestDir: "{app}\i18n"; Excludes: "i18n\lazpaint_x64.po"; Flags: ignoreversion
 Source: "{#ReleaseDir}models\*.*"; DestDir: "{app}\models"; Flags: ignoreversion
 Source: "{#ReleaseDir}readme.txt"; DestDir: "{app}"; Flags: ignoreversion