Revert "refactor: use OutputIterator for url-escaped info hash strings (#3672)"

This reverts commit 479a16787e.

libtransmission/web-utils.cc

@@ -172,6 +172,29 @@ char const* tr_webGetResponseStr(long code)
     }
 }
 
+static bool is_rfc2396_alnum(uint8_t ch)
+{
+    return ('0' <= ch && ch <= '9') || ('A' <= ch && ch <= 'Z') || ('a' <= ch && ch <= 'z') || ch == '.' || ch == '-' ||
+        ch == '_' || ch == '~';
+}
+
+void tr_http_escape_sha1(char* out, tr_sha1_digest_t const& digest)
+{
+    for (auto const b : digest)
+    {
+        if (is_rfc2396_alnum(uint8_t(b)))
+        {
+            *out++ = (char)b;
+        }
+        else
+        {
+            out = fmt::format_to(out, FMT_STRING("%{:02x}"), unsigned(b));
+        }
+    }
+
+    *out = '\0';
+}
+
 //// URLs
 
 namespace