Remove openssl_fips in common.gypi

When building native modules with old node this will cause errors:
gyp: name 'openssl_fips' is not defined while evaluating condition
'openssl_fips != ""' in binding.gyp while trying to load binding.gyp

Author: zcbenz

common.gypi

@@ -38,7 +38,7 @@
         'OBJ_DIR': '<(PRODUCT_DIR)/obj.target',
         'V8_BASE': '<(PRODUCT_DIR)/obj.target/deps/v8/tools/gyp/libv8_base.a',
       }],
-      ['openssl_fips != ""', {
+      ['"" != ""', {
         'OPENSSL_PRODUCT': 'libcrypto.a',
       }, {
         'OPENSSL_PRODUCT': 'libopenssl.a',