Tests: removed unnecessary http2 directives from grpc_ssl.t.

They were blindly copied from grpc.t and aren't required here.

grpc_ssl.t

diff --git a/grpc_ssl.t b/grpc_ssl.t
index 41bac32..1740c7f 100644
--- a/grpc_ssl.t
+++ b/grpc_ssl.t
@@ -56,10 +56,6 @@
         ssl_verify_client optional;
         ssl_client_certificate client.crt;
 
-        http2_max_field_size 128k;
-        http2_max_header_size 128k;
-        http2_body_preread_size 128k;
-
         location / {
             grpc_pass 127.0.0.1:8082;
             add_header X-Connection $connection;
@@ -70,10 +66,6 @@
         listen       127.0.0.1:8080 http2;
         server_name  localhost;
 
-        http2_max_field_size 128k;
-        http2_max_header_size 128k;
-        http2_body_preread_size 128k;
-
         location / {
             grpc_pass grpcs://127.0.0.1:8081;
             grpc_ssl_name localhost;