journal-remote: let user specify just the main part of the url

We can append /upload ourselves.

src/journal-remote/journal-upload.c

@@ -396,7 +396,13 @@ static int setup_uploader(Uploader *u, const char *url, const char *state_file)
         memzero(u, sizeof(Uploader));
         u->input = -1;
 
-        u->url = url;
+        if (!startswith(url, "http://") && !startswith(url, "https://"))
+                url = strappenda("https://", url);
+
+        u->url = strappend(url, "/upload");
+        if (!u->url)
+                return log_oom();
+
         u->state_file = state_file;
 
         r = sd_event_default(&u->events);
@@ -424,6 +430,8 @@ static void destroy_uploader(Uploader *u) {
         free(u->last_cursor);
         free(u->current_cursor);
 
+        free(u->url);
+
         u->input_event = sd_event_source_unref(u->input_event);
 
         close_fd_input(u);

src/journal-remote/journal-upload.h

@@ -23,7 +23,7 @@ typedef struct Uploader {
         sd_event *events;
         sd_event_source *sigint_event, *sigterm_event;
 
-        const char *url;
+        char *url;
         CURL *easy;
         bool uploading;
         char error[CURL_ERROR_SIZE];