figure_maker.py: fix create_df_summary for barplot

2 jobs for master in 55 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Unittest
passed #372
tests

00:00:47

 
  Quality
failed #373
allowed to fail
sonarqube-check

00:00:08

 
Name Stage Failure
failed
sonarqube-check Quality
	at java.base/java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.base/java.net.SocksSocketImpl.connect(Unknown Source)
at java.base/java.net.Socket.connect(Unknown Source)
at org.sonarsource.scanner.api.internal.shaded.okhttp.internal.platform.Platform.connectSocket(Platform.java:130)
at org.sonarsource.scanner.api.internal.shaded.okhttp.internal.connection.RealConnection.connectSocket(RealConnection.java:263)
... 31 more
ERROR:
ERROR: Re-run SonarScanner using the -X switch to enable full debug logging.
ERROR: Job failed: exit code 1