Node.js: provide reasonable default paths for macOS.

src/nodejs/unit-http/binding_pub.gyp

@@ -7,9 +7,28 @@
             ['OS=="mac"', {
               'xcode_settings': {
                 'GCC_ENABLE_CPP_EXCEPTIONS': 'YES'
-              }
+              },
-            }]
+              'conditions': [
-        ],
+                  [ 'target_arch=="arm64"', {
+                      'include_dirs': [
+                          '/opt/homebrew/include'
+                      ],
+                      'libraries' : [
+                          '-L/opt/homebrew/lib',
+                          '-lunit'
+                      ],
+                  }],
+                  ['target_arch=="x64"', {
+                      'include_dirs': [
+                          '/usr/local/include',
+                      ],
+                      'libraries' : [
+                          '-L/usr/local/lib',
+                          '-lunit'
+                      ],
+                  }]
+              ]}
+            ]],
         'sources': ["unit.cpp", "addon.cpp"],
         'libraries': ["-lunit"]
     }]