Mark buffer variables const.

include/curl_wrapper.hpp

@@ -124,7 +124,7 @@ public:
     {
         char *cbuf{curl_easy_escape(_connection, url.data(),
                                     static_cast<int>(url.size()))};
-        string sbuf{cbuf};
+        const string sbuf{cbuf};
         curl_free(cbuf);
         return sbuf;
     }
@@ -146,7 +146,7 @@ public:
     {
         char *cbuf{curl_easy_unescape(_connection, url.data(),
                                       static_cast<int>(url.size()), nullptr)};
-        string sbuf{cbuf};
+        const string sbuf{cbuf};
         curl_free(cbuf);
         return sbuf;
     }

src/connection.cpp

@@ -70,7 +70,7 @@ string Connection::get_new_stream_contents()
 {
     buffer_mutex.lock();
     auto &buffer{get_buffer()};
-    auto buffer_copy{buffer};
+    const string buffer_copy{buffer};
     buffer.clear();
     buffer_mutex.unlock();
     return buffer_copy;