graalpy -v should not override Truffle log level

* It's a CPython-compatible flag and should only set the Python flag, not touch log levels.
* Otherwise `graalpy --log.level=FINE -v ...` is actually at INFO and not FINE level which is very confusing.

(cherry picked from commit cea4899)

Author: eregon

graalpython/com.oracle.graal.python.shell/src/com/oracle/graal/python/shell/GraalPythonMain.java

@@ -778,9 +778,6 @@ protected void launch(Builder contextBuilder) {
             contextBuilder.option("python.IntMaxStrDigits", Integer.toString(intMaxStrDigits));
         }
         contextBuilder.option("python.DontWriteBytecodeFlag", Boolean.toString(dontWriteBytecode));
-        if (verboseFlag) {
-            contextBuilder.option("log.python.level", "INFO");
-        }
         contextBuilder.option("python.QuietFlag", Boolean.toString(quietFlag));
         contextBuilder.option("python.NoUserSiteFlag", Boolean.toString(noUserSite));
         contextBuilder.option("python.NoSiteFlag", Boolean.toString(noSite));