When compiling with GCC 7.5, non-trivial initializers are unsupported.

[    9s] shrpx_http_test.cc: In function 'void shrpx::test_shrpx_http_create_altsvc_header_value()':
[    9s] shrpx_http_test.cc:152:9: sorry, unimplemented: non-trivial designated initializers not supported
[    9s]          },
[    9s]          ^
[    9s] shrpx_http_test.cc:152:9: sorry, unimplemented: non-trivial designated initializers not supported
[    9s] shrpx_http_test.cc:153:5: error: no matching function for call to 'std::vector<shrpx::AltSvc>::vector(<brace-enclosed initializer list>)'
[    9s]      };
[    9s]      ^

Index: nghttp2-1.60.0/src/shrpx_http_test.cc
===================================================================
--- nghttp2-1.60.0.orig/src/shrpx_http_test.cc
+++ nghttp2-1.60.0/src/shrpx_http_test.cc
@@ -143,14 +143,12 @@ void test_shrpx_http_create_affinity_coo
 void test_shrpx_http_create_altsvc_header_value(void) {
   {
     BlockAllocator balloc(1024, 1024);
-    std::vector<AltSvc> altsvcs{
-        AltSvc{
-            .protocol_id = StringRef::from_lit("h3"),
-            .host = StringRef::from_lit("127.0.0.1"),
-            .service = StringRef::from_lit("443"),
-            .params = StringRef::from_lit("ma=3600"),
-        },
-    };
+    AltSvc s;
+    s.protocol_id = StringRef::from_lit("h3");
+    s.host = StringRef::from_lit("127.0.0.1");
+    s.service = StringRef::from_lit("443");
+    s.params = StringRef::from_lit("ma=3600");
+    std::vector<AltSvc> altsvcs = {s};
 
     assert_stdstring_equal(
         R"(h3="127.0.0.1:443"; ma=3600)",
@@ -159,19 +157,15 @@ void test_shrpx_http_create_altsvc_heade
 
   {
     BlockAllocator balloc(1024, 1024);
-    std::vector<AltSvc> altsvcs{
-        AltSvc{
-            .protocol_id = StringRef::from_lit("h3"),
-            .service = StringRef::from_lit("443"),
-            .params = StringRef::from_lit("ma=3600"),
-        },
-        AltSvc{
-            .protocol_id = StringRef::from_lit("h3%"),
-            .host = StringRef::from_lit("\"foo\""),
-            .service = StringRef::from_lit("4433"),
-        },
-    };
+    AltSvc s1, s2;
+    s1.protocol_id = StringRef::from_lit("h3");
+    s1.service = StringRef::from_lit("443");
+    s1.params = StringRef::from_lit("ma=3600");
+    s2.protocol_id = StringRef::from_lit("h3%");
+    s2.host = StringRef::from_lit("\"foo\"");
+    s2.service = StringRef::from_lit("4433");
 
+    std::vector<AltSvc> altsvcs = {s1, s2};
     assert_stdstring_equal(
         R"(h3=":443"; ma=3600, h3%25="\"foo\":4433")",
         http::create_altsvc_header_value(balloc, altsvcs).str());