Makefile wasn't producing licenses at the right step, try and detect if elevated from the NSIS installer from the start of the script, for now, fail if we aren't

Makefile

@@ -39,7 +39,7 @@ prep: profile.tgz app-profile.tgz profile build/licenses build/I2P build/I2P/con
 	cp src/nsis/*.nsh build
 	cp src/icons/*.ico build
 
-install.exe:
+install.exe: build/licenses
 	cd build && makensis i2pbrowser-installer.nsi && cp I2P-Profile-Installer-*.exe ../ && echo "built windows installer"
 
 export RES_DIR="../i2p.i2p.jpackage-build/installer/resources"

src/nsis/i2pbrowser-installer.nsi

@@ -144,6 +144,13 @@ Page instfiles
 !include i2pbrowser-mozcompat.nsi
 
 Function .onInit
+    UserInfo::GetAccountType
+    pop $0
+    ${If} $0 != "admin"
+        MessageBox mb_iconstop "Administrator rights required!"
+        SetErrorLevel 740 ;ERROR_ELEVATION_REQUIRED
+        Quit
+    ${EndIf}
     !insertmacro MUI_LANGDLL_DISPLAY
     Call ShouldInstall64Bit
     ${If} $0 == 1