Skip calls that don't exist

Sometimes tempest logs accidentally concatenate multiple lines.  This
may prevent some lines from being parsed.

fairy_slipper/cmd/tempest_log.py

@@ -71,6 +71,11 @@ class DB(object):
     def _normalize_headers(self, headers):
         return {k.lower(): v for k, v in headers.items()}
 
+    def exists(self, req):
+        if req in self.requests:
+            return True
+        return False
+
     def create(self, req, request):
         url = urlparse.urlsplit(request['url'])
         port = url.netloc.split(':')[-1]
@@ -173,6 +178,14 @@ def parse_logfile(log_file):
                     log.warning('Failed to find body to add to.')
                 continue
 
+            if not current_req_id:
+                continue
+
+            if not db.exists(current_req_id):
+                log.warning("Can't find request %r" % current_req_id)
+                current_req_id = ''
+                continue
+
             key = key.strip()
             value = value.strip()