[MCOMPILER-457] Change showWarnings to true by default

Co-authored-by: Slawomir Jaranowski <s.jaranowski@gmail.com>
diff --git a/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java b/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java
index 99793f8..ea37a4d 100644
--- a/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java
+++ b/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java
@@ -174,9 +174,9 @@
     private boolean optimize;
 
     /**
-     * Set to <code>true</code> to show compilation warnings.
+     * Set to <code>false</code> to disable warnings during compilation.
      */
-    @Parameter( property = "maven.compiler.showWarnings", defaultValue = "false" )
+    @Parameter( property = "maven.compiler.showWarnings", defaultValue = "true" )
     private boolean showWarnings;
 
     /**