Fix dropwizard parsing error for metrics that need escaped (#4142)

If the dropwizard parser cannot convert the metric name into a valid
line protocol series then we will accept the name as is.

plugins/parsers/influx/machine.go.rl

@@ -221,6 +221,8 @@ discard_line :=
 # main machine.
 align :=
 	(space* comment)* space* measurement_start @hold_recover %eof(yield);
+
+series := measurement tagset $err(parse_error) eol;
 }%%
 
 %% write data;
@@ -242,12 +244,30 @@ type machine struct {
 	p, pe, eof int
 	pb         int
 	handler    Handler
+	initState  int
 	err        error
 }
 
 func NewMachine(handler Handler) *machine {
 	m := &machine{
 		handler: handler,
+		initState: LineProtocol_en_align,
+	}
+
+	%% access m.;
+	%% variable p m.p;
+	%% variable pe m.pe;
+	%% variable eof m.eof;
+	%% variable data m.data;
+	%% write init;
+
+	return m
+}
+
+func NewSeriesMachine(handler Handler) *machine {
+	m := &machine{
+		handler: handler,
+		initState: LineProtocol_en_series,
 	}
 
 	%% access m.;
@@ -269,7 +289,7 @@ func (m *machine) SetData(data []byte) {
 	m.err = nil
 
 	%% write init;
-	m.cs = LineProtocol_en_align
+	m.cs = m.initState
 }
 
 // ParseLine parses a line of input and returns true if more data can be