Unnecessary encoding of authentication token for influxdb

[duese]

The code that processes the authentication token for InfluxDB is currently encoded to ISO_8859_1 which is unnecessary as kamon.influxdb.authentication.token must already be provided as a base64 encoded string.

An ISO_8859_1 encoded token also may raise an IllegalArgumentException:

java.lang.IllegalArgumentException: Unexpected char 0x2026 at 84 in Authorization value: Token [size=88 text=68F_F281rk1J68Nui-y1gooWrs55-I-FI9qWIj1phyzn-5KbK7n3tJvQvssPQ3h7?]
	at okhttp3.Headers.checkValue(Headers.java:284)
	at okhttp3.Headers$Builder.set(Headers.java:415)
	at okhttp3.Request$Builder.header(Request.java:184)
	at kamon.influxdb.InfluxDBReporter$$anon$1.intercept(InfluxDBReporter.scala:210)
	at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:142)
	at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:117)
	at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:229)
	at okhttp3.RealCall.execute(RealCall.java:81)
	at kamon.influxdb.InfluxDBReporter.$anonfun$reportPeriodSnapshot$1(InfluxDBReporter.scala:52)
	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
	at scala.util.Try$.apply(Try.scala:213)
	at kamon.influxdb.InfluxDBReporter.reportPeriodSnapshot(InfluxDBReporter.scala:51)
	at kamon.module.ModuleRegistry.$anonfun$scheduleMetricsTick$1(ModuleRegistry.scala:258)
	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
	at scala.concurrent.Future$.$anonfun$apply$1(Future.scala:659)
	at scala.util.Success.$anonfun$map$1(Try.scala:255)
	at scala.util.Success.map(Try.scala:213)
	at scala.concurrent.Future.$anonfun$map$1(Future.scala:292)
	at scala.concurrent.impl.Promise.liftedTree1$1(Promise.scala:33)
	at scala.concurrent.impl.Promise.$anonfun$transform$1(Promise.scala:33)
	at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:64)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:834)

with the following application.conf:

kamon {
  instrumentation.akka.filters {
    actors.doomsday-wildcard = on
    actors.track {
      includes = [
         "BpcICSystem/user/SomeService"
      ]
    }
    dispatchers {
      includes = [ "**" ]
      #excludes = [ "**" ]
    }
    routers {
      includes = [ "**" ]
      #excludes = [ "**" ]
    }
  }

  influxdb {
    hostname = "my_hostname"
    protocol = "http"
    database = "my_db"
    
    # Workaround for #1129:
    token = "68F_F281rk1J68Nui-y1gooWrs55-I-FI9qWIj1phyzn-5KbK7n3tJvQvssPQ3h7VkJor0cLSMwsWelBRljuJA=="
    authentication {
      # See PR #1130 
      token = "68F_F281rk1J68Nui-y1gooWrs55-I-FI9qWIj1phyzn-5KbK7n3tJvQvssPQ3h7VkJor0cLSMwsWelBRljuJA=="
    }
  }
}