Allow secondary constructors without body

#KT-6967 Fixed

idea/testData/formatter/SecondaryConstructors.after.kt

@@ -8,8 +8,7 @@ class A {
     fun foo() {
     }
 
-    constructor() {
-    }
+    constructor()
 
     fun foo() {
     }
@@ -55,8 +54,7 @@ class A {
     constructor() : this() {
     }
 
-    constructor() : this() {
-    }
+    constructor() : this()
 
     constructor() : super() {
     }

idea/testData/formatter/SecondaryConstructors.kt

@@ -2,7 +2,7 @@ class A {
     constructor() {}
     constructor() {}
     fun foo() {}
-    constructor() {}
+    constructor()
     fun foo() {}
     constructor() {}
     val x = 1
@@ -26,6 +26,6 @@ constructor() {}
     constructor()   : this() {}
 constructor():this() {}
 
-    constructor(): this   () {}
+    constructor(): this   ()
     constructor(): super(){}
 }

idea/testData/formatter/secondaryCtorLineBreak.after.inv.kt

@@ -18,6 +18,8 @@ class A {
     {
     }
 
+    constructor()
+
     constructor() {
     }
 }

idea/testData/formatter/secondaryCtorLineBreak.after.kt

@@ -22,6 +22,8 @@ class A
     {
     }
 
+    constructor()
+
     constructor()
     {
     }

idea/testData/formatter/secondaryCtorLineBreak.kt

@@ -18,6 +18,7 @@ class A {
 
     {}
 
+    constructor()
     constructor() {
     }
 }